This is a one-shot of pregnant Linstead for the two anons that asked on my Tumblr, enjoy!

/

She first realized that morning she couldn't bring herself to go on a run with him. Running every morning before work was something they had started to do when Jay first joined the unit, claiming it would help to break the ice. She sat up in bed, watching him tie his shoes and pulling a hoodie over his head, when her world started to spin. By the time she managed to make it to the bathroom, he had left and she emptied her stomach. When he got back an hour later, he noticed the dark circles under her eyes and he noticed her fatigue.

"You okay? You look kinda tired."

"Yeah… I didn't sleep too well." She tried her best to focus on her task at hand, avoiding his gaze because she knew those piercing blue eyes could get her to do anything, and that included telling the truth.

"I thought you'd be exhausted after last night." There was a sign of teasing in his voice as he placed a kiss to her temple, reaching for the keys on the countertop she leaned against. She turned to face him, allowing him access to her lips, before she slipped the keys out of his hand.

"I don't think so."

/

Her nausea didn't go away as they made it to work. Driving managed to keep her focus on the road rather than her stomach that was doing somersaults. As they reached the district, she tried her best to play up the facade whenever someone was in her presence.

She excused herself from the bullpen multiple times as the need to empty her stomach would arise. After the second time, she could see the worry etched on Jay's face. She could feel his eyes following her out as she made it to the bathroom in the locker room, it sent a shiver up her spine.

After the third time she quickly walked out of the bullpen, he followed her. She had no idea that he was behind her, until she felt the cool cloth on the back on her neck after she flushed the toilet.

"Is this why you didn't wanna go on a run with me?" She slowly nodded her head, finally meeting his gaze which was full of anxiety.

"It's probably just a stomach bug, don't worry about it." She swished water in her mouth a few times in the sink before wiping her mouth.

"Well you should go home and rest."

"I'll be fine I just-"

"Babe… I don't think so." He closed the space between them and set his hands on her hips. "It's just paperwork today, go home. Besides, I don't want to kiss you until you've brushed your teeth." That earned him a light punch to his shoulder before she turned to her locker, extracting her bag.

/

On her way home, she stopped by the drug store. She needed to confirm her suspicions before she entirely changed Jay's life. She was 99.9% sure she was pregnant, their intimacy schedule seemed to line up with the date. Not to mention she missed her period.

Standing in the aisle with all the pregnancy needs, her apprehension and anxiety seemed to increase. Her heart started beating hard that she was sure she'd have a heart attack. She decided on 3 different pregnancy tests, including one that would tell her about the test on an app on her phone.

When she walked through the front door of her apartment, the first thing she did was download the app. She opened all the packages and set them out on the bathroom counter while she waited for the app to finish synchronizing.

There's always a disagreement with which minute is longer: A microwave minute or a minute on the treadmill. But Erin was sure she figured out that waiting on a pregnancy minute was by far the worst. And she had to wait for 3. She paced around the apartment trying to busy herself in something, but Jay already had cleaned every crevice of their place. So she sat on the bed, waiting.

The alarm on her phone made her jump, but she was quick to turn it off, returning to the app letting her know whether or not she was pregnant. She turned her gaze to the other two manual tests on the counter, and sighed heavily before she looked directly at them. Sure enough, there were two little plus signs on them: Pregnant. When she looked at her phone, it too said she was pregnant, it even gave her a due date. January 2nd, 2018.

She sunk to her knees against the wall, feeling the tears stinging her eyes. All Erin wanted at this moment was to feel Jay's arms wrapping around her as he whispered reassurances into her ear. But all she had was herself at the moment, and that would have to suffice.

When Jay walked into the apartment later that day, he was greeted by silence. Nothing had changed since he had left that morning, except for the boots that lay haphazardly by the front door. He straightened her boots and placed them next to his, before turning towards the bedroom. He found her asleep in their bed, the sheets only covering her legs, and she was softly snoring. He brought the covers over her body before he placed a kiss on her forehead, leaving towards the kitchen.

/

The next morning started out the same. Jay went for his run and Erin's face was in the toilet. She stayed home again, under protest, and Jay promised he'd call to check in on her. Erin didn't know why she couldn't bring herself to tell Jay. Maybe it was the uncertainty of the future and what a child could mean to their careers, or maybe it was because she didn't see herself being a mother, at least not yet.

Getting a whiff of anything would send her stomach into knots, so she couldn't manage to eat anything. She knew she should be eating, and she also knew the nausea wouldn't settle for a while, unless she went to a doctor to get anti-nausea pills safe for pregnant women prescribed. And going to a doctor meant telling Jay. She promised herself it'd be the first thing she'd tell him when he gets home later in the evening.

/

When he came and sat down on the couch next to her later that day, she tried to keep her mind engrossed in the Blackhawks game. He brought them both beers from the fridge, but she just left hers to warm up on the coffee table.

"I guess your stomach isn't settled enough for beer yet?"

"Yeah about that…" He turned his gaze from the TV to her, watching the worry lines on her face deepen.

"I don't think I'll be drinking for a bit." He raised his brow at her in his signature Halstead way.

"Um, I think, well not think, I know, but I'm pregnant." Her voice started off weak, but as she finished her sentence, her voice was barely above a whisper. She watched his body language and face. She watched his forehead wrinkle and his tongue nervously licking his bottom lip before he brought the lip under his teeth. When he let go of his lip, it was because his face erupted into a smile.

"When did you find out?!" His excitement was palpable. His grin childlike.

"Yesterday when I came home from work, I grabbed a few tests at the drugstore." She got up from the couch, going into their ensuite bathroom where she was hiding the tests. When she showed them to him, she was sure she saw tears forming in his eyes. He quickly wiped them away before they fell, and before he looked back at her. She was crying too.

"C-can I see." She laughed.

"There's nothing there yet."

"I still wanna see." She obliged, lifting her shirt off her abdomen. Her stomach was still toned and flat, no sign of any baby growing inside of her. His hand was cold against her skin, making her flinch. He rubbed his thumb slowly over what would soon be a bump before placing a kiss to her stomach.

/

Their first doctor's appointment was a week later. The morning sickness continued but Erin managed to get through the work day. They decided to tell everyone after the first doctor's appointment, wanting to get the ultrasound photo. Erin was reclined on the chair while Jay stood next to her, gripping onto her hand as if his life depended on it. Ever since he found out about the baby, he didn't let Erin so anything strenuous around the apartment. He was an even closer watch at work. He never let anyone get too close to her during interrogations and his heart would drop whenever they had to go on a raid. This pregnancy was definitely going to give him grey hair.

The gel was cool on her stomach, making her flinch. The doctor talked about the next 9 months of gestation and what to expect before she moved the wand to a specific part of Erin's belly. There they saw their baby for the first time. It's heartbeat filled the room seconds later, loud and strong. It brought tears to both of the soon-to-be parents.

"Your baby is about 10 weeks old and is looking good. I just wanted to go over some things with you such as how you're physically and mentally feeling. I'm going to prescribe some pills that will help with the morning sickness and also some prenatal vitamins." The words had been muffled to Erin as she was still staring at the photo in her hands. She quickly wiped away another tear before turning her gaze to the doctor.

/

"Uh, Jay and I have something to tell you." Hank's eyes went from the paperwork on his desk to the two detectives standing in front of him. He watched Jay's eyes look at everything except him. He watched Erin lightly bouncing from one foot to the other, nervously.

"You're pregnant?"

"Wait… how did you know?"

"Well, both of you are showing it from your body language. And I'm pretty sure you're having morning sickness because you excuse yourself to use the bathroom a few times and Jay follows you like a lost puppy." Jay's eyes widened at his realization of how obvious they were in the last week. He couldn't believe he let his guard down so easily. Hank got up from his chair, approaching Erin. "Congrats, kid. Gimme a hug."

/

Third month of gestation:

The first two months passed quickly, as the couple had discovered about the baby and as they told their friends and family. At the 11th week of her pregnancy, their doctor let them know that the baby's genitals were developing and they would soon be able to find out the sex of the baby, much to the apprehension of Erin. As time went on, her fear around the baby grew. It all seemed to get more real, day by day. Jay would give her daily reminders of how what she was feeling was normal and that he too, was scared.

"Babe, we've got lots of time. And we have so much to do too. Once we start getting everything together it will get a lot more fun. Trust me."

"What, you've done this before?" She had a hint of teasing in her voice but her hormones always seemed to make her either depressed, or angry. She couldn't believe that Jay was still laying next to her in bed at the moment.

Jay turned over from his back to face Erin, subconsciously bringing his right hand to her stomach. His thumb lazily drew circles around her bellybutton, knowing his baby was in there somewhere. "Maybe I have." He smiled.

Sure enough the hormones kicked in. The teasing in her had disappeared and was now replaced with hurt and anger. The last time she had these feelings was when she found out about the woman he was married to, and how he had no intentions of telling her.

Jay quickly noticed her change in attitude as he picked up his hand from her stomach, bringing it to her cheek. "Erin, I was kidding."

She pushed his hand off of her face before turning to her other side, leaving Jay to stare at her back.

"Erin, please don't do this."

"Do what?"

"You know what I mean, don't take jokes so seriously." That comment seemed to piss her off even more.

"Geez, maybe if you get so defensive so quickly, you should just leave." He knew she didn't mean that, but it hurt anyways.

"Erin." He sat up in bed, peering over her shoulder to look at her face. He rested his chin on her arm as he rubbed his hand up and down her back. "I'm sorry." He placed a kiss on her cheek, and then her neck where he knew she was most sensitive.

"Erin, please look at me." He could tell she was silently crying due to the hormones and he felt like complete shit for making her cry. He forced her to lie on her back again, before he got up to straddle her hips. "I don't have a kid, except for the one in you. And if I did, I would've told you."

His hands lifted her camisole top before they rested on her abdomen. He placed light kisses over her stomach, before he brought his lips to hers.

"Jay Halstead, you sure know how to make a girl feel better." Her voice came out seductive before she started pulling on the hem of his shirt.

/

Fourth month of gestation:

The fourth month was when Erin started to pop and her morning sickness started to ease. She started to gain her pregnancy weight as the baby's body started to grow. Listening to the baby's heartbeat every appointment seemed to leave the couple in a state of solace. Their job was stressing, even with Erin on desk duty. The doctor had told her to take a few days off, that stressing wasn't going to do any favours to the baby's development. Reluctantly, she agreed.

Jay had also decided to take some furlough, but it was honestly just to make sure Erin rested. They would take walks to the park and would relax under the sun. Jay tried his best to keep Erin off of her feet at home, which seemed like a difficult task. However, he managed to bribe her with foot rubs, so whenever she felt like it, she'd rest her feet in his lap, and he'd rub the tension away. He was sure his thumbs would soon detach from his hands from the amount of foot rubs he had given. But he'd do anything for Erin, so he continued.

At the week 15 ultrasound, they saw their child sucking its thumb. It brought tears to Jay's eyes and Erin loved seeing the love and happiness he displayed over his face. Their doctor let them know that Erin would soon need to get a blood test to screen for Down syndrome. It was called a quadruple marker screening test. The happiness had soon evaporated, only to be replaced with worry.

The worry didn't last long, as the baby startled to move around during week 16. The first time Erin felt it, Jay wasn't there. She felt the fluttering of the baby every now and then, and it brought tears to her eyes. When he arrived home later that evening, she was quick to meet him at the door. She told him what she felt earlier that day and he made her promise that the next time their baby moved, he wanted to make sure to feel it.

Week 16 was a big one. They could find out the gender of their baby. Jay and Erin had discussed the pros and cons over and over again, but they still hadn't come to a decision the day of their appointment. They decided that their decision would be spontaneous when the doctor asked.

"You should stop bouncing your knee. Everything will be fine." Jay brought his gaze off of his phone to Erin's leg, before he placed his left hand down on her thigh.

"Yeah, I'm just nervous."

"Everything is okay. We don't have to find out today. We can do it next time or the time after that or even when the baby is born. It's your choice." His last words seemed to make her stomach somersault even more. He was allowing her to make the decision.

/

"So would you like to know the sex of the baby?" The doctor moved the wand over Erin's belly as Jay looked down at her expectantly.

"Uh-I-I'm…"

"No, not today. I don't think we're ready." Jay answered for Erin when he noticed her mumbling and words faltering. She looked back up at him and smiled weakly, appreciating his act. She knew he really wanted to know about the baby's gender, but she also knew he would wait until she was ready. Even if they would have to wait for the birth.

/

FIfth Month of Gestation

During her 17th week, Erin had gained even more weight. The baby was growing fast and it seemed to make Erin really fatigued. She would sometimes get dizzy or she would start feeling faint, regardless of how much she would eat. She thought that she wasn't eating enough for her and the baby, and that was why she was always dizzy.

But one evening after dinner, Erin almost collapsed on the floor after she helped Jay do the dishes. He managed to catch her before her knees hit the hardwood, and he carried her over to the couch.

"Erin, we need to go to a hospital."

"Relax Jay, the doctor said feeling faint is normal at this time of my pregnancy."

"But-"

"No buts, I'm fine."

"At least let me call Will. We won't have to go to a hospital. He'll come here. Please Erin."

"..." She sighed heavily. "Fine."

/

Will Halstead flashed the light from his flashlight in Erin's eyes before he took her blood pressure.

"Do you ever get headaches." Erin nodded her head.

"Was this the first time you've felt faint." He had moved to listen to Erin's lungs while she shook her head no.

"Well, everything is normal. You just need to rest. Also, your movements can't be as quick anymore. I know you're a cop but you still need to slow down a bit. It's likely any quick movements you did today led to your lightheadedness."

Jay smiled at his brother before he thanked him and escorted him to the door. When he returned, he watched Erin's eyes follow him as she sat on the couch.

"See, nothing was wrong like I told you."

"I'm pretty sure he still said you need to rest."

"I am resting. I'm sitting on the couch."

"Yeah well I'd like for you to rest in bed." He ended his sentence approaching Erin before he scooped her up into his arms, going towards their bedroom.

"Jay, I think I can manage a little bit of walking."

"Shhh, take a little nap." He gently placed her on the bed before placing a kiss on her forehead and tucking the covers over her.

"I'm not a child, Jay."

"But you're carrying one. So get some rest."

/

The 19th and 20th week brought her back pain. The dizziness seemed to improve, but it was still there. The baby seemed to be moving quite a bit, but for some reason it seemed to relax whenever Jay put his hand on Erin's stomach.

Her ankles started to swell and Erin was starting to take even more days off from work. She tried her best to relax at home, but she would quickly get bored once Jay would leave.

Her day was filled with binge watching TV shows before Jay would bring her food on his lunch break. They would eat together and talk about their mornings before Jay would leave for work again, leaving Erin to the silence of their apartment.

When Jay would get home in the evening, Erin would be his first priority. He would ask about her day, how much she had eaten and how she was feeling. He would make her dinner before they would cuddle up on the couch, watching a movie, enjoying each other's presence.

Around 11, Erin would start to doze off and Jay would lead her to the bedroom, helping her get comfortable. He would slowly rub her back, relieving some tension as she would fall asleep. They would repeat the same process the next day if she wasn't feeling well.

/

Sixth month of Gestation

Around the 21st week, Erin started to really show. She had gained about 10 pounds since the beginning of her pregnancy and her shirts were becoming too small. Jay and Erin decided on attending childbirth classes, to help relieve some stress. They would be going once a week after work on Mondays and it genuinely seemed to relieve Erin's stress.

One Monday, Jay couldn't go. They were working a case through the weekend and Voight really needed him to stay. So Erin went to the birthing class with the next best thing: Will. He was Jay's brother so it was basically the same thing.

That was until they walked into the class and sat down on the rug together that she realized the differences between Will and Jay. Will was like a teenage boy in a sex ed class. He would try to hide his laughter whenever an instructor would talk about pushing the child out of her vagina.

"You're a doctor, why are you even laughing?" Erin shot Will a disapproving look.

"I'm an ED doctor, not a OB. Some stuff is kinda funny." He tried to hold in another chuckle, but it still slipped out. Erin just rolled her eyes at him. This was the last time she was bringing Will anywhere with her.

The next week, thankfully, Jay had returned to the classes. The instructor decided to take the couples up to the nursery of the hospital. They each looked through the glass to watch the newborn babies either sleeping, crying or simply being awake. Erin watched the joy on Jay's face and it brought happy tears to her eyes. The love this man had for everything was admiring.

His gaze had caught a little baby girl, she was awake and alert and she took in her surroundings. She was a little bit bigger than a football and his eyes never left her, taking in her size. He couldn't wait until he would be holding his own bundle of joy.

/

Seventh month of Gestation

The first time she experienced Braxton Hicks, her breath had caught in her throat. She was sitting at her desk when she felt that pain. She tried to ignore it but it happened again. Her gaze lifted from her work on her desk up to Jay's. He immediately took his eyes off of his computer screen and looked back at her. He knew exactly what that terrified look meant. It was too early.

He quickly stood up, grabbing his keys and jacket before escorting her down the stairs. He used his sirens, it was an emergency.

When they made it to the hospital, they were quickly greeted by Natalie. She did a complete check over before telling them that everything was okay, that the contractions were normal.

"You gave me a scare." Jay smiled before he placed a kiss on Erin's lips.

"It wasn't me, blame the baby." Jay bent down in front of Erin's stomach, rubbing his thumbs over her stomach over the hospital gown.

"You stay in there for a little bit more. I know you're excited but we are too. Only 2 more months and you can come out and see the world. C'mon let's get you two home."

/

"Oh, come on." Erin readjusted her position in bed for the 10th time since they had woken up 15 minutes earlier.

"What, what's wrong?!" Jay's head shot up off of his pillow as he looked over to Erin who was now sitting up in bed.

"Your kid is kicking me in the ribs."

"Our kid." He corrected. "It must've been all the sugar you had last night." The couple had binged out on ice cream for dinner the night before.

"Well, we're never doing that again."

"Yeah, we'll see about that."

/

Eighth Month of Gestation

They had another ultrasound that morning. And once again the doctor asked whether or not they'd like to know the gender of the baby. By this point, both Jay and Erin agreed to wait until the birth, it was only a month away.

The 32nd and 33rd week of pregnancy meant a lot of growing for the baby. The baby was growing quickly which meant Erin was constantly making trips to the bathroom. It annoyed her quite a bit, especially since she barely needed to pee. She couldn't wait to give birth.

She was officially on maternity leave and her days were spent with her feet reclined and with pillows behind her back. She didn't mind staying home as she would get exhausted quickly and would need to sit. She was eating a lot which made her feel bloated all the time so leaving the apartment wasn't her priority.

Their friends started to bet on what they think they would have. $5 on each bet. There was a board taking over the breakroom at work which had names of their colleagues and friends listed under 'Girl' and 'Boy'. It was completely half and half. Only those who hadn't seen the ultrasound photo from Med were allowed to participate, so Will and Nat were disqualified.

Laying in bed later that night, Erin finally asked Jay a question that had been on her mind for a while.

"Jay… what do you think we're having?"

He took his time to answer, only making Erin's anxiety increase.

"Well, I've always seen me having a boy. It's a Halstead thing. Me and Will. My Dad and his brother. And so on. But I've always wanted a girl. But most importantly, I just want a healthy baby, I don't care whether it's a boy or girl." She smiled at his comment. "What about you?"

"Honestly, I don't even know."

"C'mon, it's a 50/50 chance."

"I just don't want to be wrong."

"Hey… it's just me here."

"Still. A mother shouldn't be wrong."

"Erin, it's okay."

/

Ninth Month of Gestation

It was by far the worst month of her pregnancy. She felt fat and bloated all the time and she always felt fatigued. Her doctor had told her to be on bed rest for a week to see if she would have any improvement. The baby seemed to be dropping from higher into her ribs down her pelvis. She was hoping the day would come soon.

They had bags packed and ready to go for whenever the baby was ready. One bag for Erin and her essentials, one for Jay, and one full of things for the newborn baby. They had neutral coloured clothing, diapers and lots of pacifiers.

The baby's room was painted a warm grey colour, with help from the unit, and white furniture was placed around the bedroom. A crib against the wall, a changing table adjacent to it, and a rocking chair in the corner. There were pictures of the family the baby would grow to know. Pictures of the unit at the 21st, the firefighters at 51, and the doctors down at Med. In the centre was a photo of Jay and Erin. It was one of their maternity photos with Jay's hands resting on her stomach.

/

The due date had come and passed and there was no signs of Erin being in labour. The baby continued to move inside of her but it didn't seem like it wanted to come out. She tried everything. Yoga, walking, spicy foods and even uncomfortable sex. But nothing seemed to be working. They decided that they would let the doctor break Erin's water instead.

The night before they were supposed to go into the hospital, they spent as much time as they could together. The next night they would be spending in this apartment, there would be 3 Halsteads. They watched a movie and cuddled on the couch before falling asleep.

Jay was woken up a couple hours later, with Erin no longer next to him. He spotted her looking out the window. He quietly came up behind her and rested his chin on her shoulder, automatically bringing his arms to wrap around her.

"You okay?"

"Yeah, just a bit nervous."

"It's natural to be. Why don't you come get some sleep? You'll need at the strength you can get in the morning."

"Yeah, I guess so."

/

She was in labour for over 9 hours that day. Jay never left her side and he held her hand through every contraction, even if he was sure she'd break his hand. Both of the soon-to-be parents were apprehensive the entire day. It wasn't until the baby's screams were filling the room that the tension they were feeling evaporated, as they both looked down at the newest boy in the Halstead family lying on Erin's chest.