After reading some of your comments, I decided to change one line in the previous chapter. You guys are right, Cragen wouldn't be 'sure' of his Detectives having an affair. So I changed his line to "I could have sworn …", which refers to how Olivia and Elliot had been acting since Olivia told Elliot she was pregnant. He mistook their understanding for something else.
Well, without further ado, let's go see the doctor!

...

4. Heartbeat

When Elliot walks into the precinct on the day of Olivia's doctor's appointment, there is a storm in his eyes. He strides over to the coat rack to hang up his coat and then heads over to the coffee maker without a word.

Olivia hasn't slept much, feeling nervous about the appointment, and doesn't think she can handle an angry Elliot today. He is tense and she follows him with her eyes until he sits down across from her. His jaw is set and he doesn't look at her. Before she can ask him what's the matter, she sees Elise wander into the squad room. They haven't solved her rape case yet because the perp's DNA isn't in the system, and Olivia had been too busy with herself to do a follow-up phone call with her. She feels guilty about that now and stands up to greet Elise.

The young woman's eyes are filled with horror and Olivia wraps an arm around her instinctively.

"What is it honey?" she coos, leading her to the family room.

"I saw him!" Elise exclaims. "I saw him at the hardware store!"

Elliot stands up as well, grabbing a notepad and pen, and follows them into the family room.

They talk to Elise for a while and then Elliot heads out with Munch to see if the hardware story has any security camera recordings. Olivia tends to Elise, who is still shaking despite being dressed in multiple layers of clothing, after seeing her attacker so unexpectedly. She was too shocked to see where the man had gone but Olivia assures her that she was very wise to come over right away. She offers to drive Elise home to her sister's and Elise accepts her offer. Olivia checks the time before heading out, hoping she'll be back in time for her doctor's appointment.

…

When she returns to the station a while later, Elliot is already waiting for her.

"We should get going if you wanna be on time," he tells her. "Traffic is a bitch at the moment."

"Yeah, I noticed," Olivia says. "But what do you mean 'we'?"

"I'm coming with you. You shouldn't be doing this alone," Elliot says.

"Says who?" she challenges him instantly. "I know I'm going to be a single parent, Elliot. I'm used to doing everything on my own."

"I know. But you're not doing this alone. I told you I'd be here for you."

Olivia sighs.

"I know El, and I appreciate it a lot. Really. But ... you don't have to hold my hand through the whole thing. Next you're gonna tell me you want to be there when I give birth," Olivia jokes, but when she sees the look on Elliot's face, she realizes that it's actually true.

"El … It's very sweet of you but I'm not sure I'll even want you there. What will Kathy think?"

Elliot tenses up at the mention of his wife's name and he turns away from her to close his desk drawer.

"That doesn't matter," he says tersely. "Now let's go. We can talk on the way."

Olivia gives in and follows her partner out because they really need to get going. She is nervous about the appointment and is actually glad to have some company. But Elliot is very tense and she wonders why.

She glances at him a few times during the drive to the clinic she has chosen and finally asks him,

"Elliot. Please tell me what's going on with you. I don't know how to deal with this right now."

She knows she is exploiting her pregnancy a little to get him to open up to her, but she doesn't care. She could deal with his brooding like she always has; she just doesn't want to.

Elliot sighs and doesn't seem eager to share with her what's bugging him.

"Did I do something wrong?" she asks, although she can't think of anything.

They've been getting along better than ever lately. Elliot is an expert at navigating through her hormonal outbursts and is displaying a level of patience with her that is uncharacteristic of him. He's even helped her clean up when she missed the trash can once, throwing up after seeing blood at the lab. She thinks she's only ever seen him like this with his children. His concern for her is almost fatherly and it is really helping her more than she cares to admit that someone is looking out for her.

But something's been off ever since he came into work this morning.

"I don't want to bother you with my troubles," Elliot tells her.

"I've been bothering you with mine non stop Elliot. I may be pregnant but you can still talk to me, you know."

She can tell Elliot is still clamming up on her and she wonders if it has to do with the rumors flying around the precinct, now that word is getting out that she's pregnant.

"If it's about what people are saying about us, I can take it," she assure Elliot.

"I know," he responds, a little too quickly. "Just … let's just go to your appointment. It's an exciting day for you and I don't want to ruin it with my petty problems."

Olivia sighs. She knows they can't be petty problems if this is Elliot's reaction, but decides to give him a pass for now. Today should be about her and the baby.

…

The Doctor greets them kindly and introduces herself as Camilla Simmons. Olivia takes an instant liking to the woman, who is about ten years older than she is. She bites her lip when the woman asks Elliot innocently if he's the daddy.

Elliot exchanges a glance with her that seems to say 'not again', but he manages a smile.

"No Doctor. I'm a friend."

"My best friend," Olivia adds. "The daddy isn't in the picture."

"How nice of you to support your friend," doctor Simmons says with a warm smile. "Olivia, I've just read the form you filled out with the nurse. You think you're about eight and a half weeks along?"

"Yeah. I was hoping to hear the baby's heart today," Olivia says and the doctor goes to work.

Olivia is a little disappointed when the doppler can't pick up the baby's heartbeat yet, but when the nurse wheels in the ultrasound machine, she can't stop grinning. Seeing her baby will be even better than hearing it. Elliot puts a hand on her shoulder and Olivia squeezes it. She's very happy now that he came along. It's good to share these special moments with someone else.

"This is going to be a little cold," the Doctor announces after asking Olivia to undo her slacks and pull up her shirt, and before squirting some gel on her lower abdomen.

Olivia doesn't care, as long as she gets to see her baby. After a few moments of moving the stick across her belly, the doctor announces,

"And there is little baby Benson."

Olivia's eyes widen when she sees the grey blob in the middle of the screen. There is a tiny flutter in the middle of the blob.

"Is that the heart beating?" she asks, in awe of what she's seeing.

"It is," the Doctor confirms, and Olivia squeezes Elliot's hand tighter.

"Amazing," Elliot whispers, and when Olivia looks up at him, she can see a sheen of tears in his eyes.

"El," she says softly, and he looks down at her.

"That's your baby, Liv," he says, as if he can hardly believe it. "It's a new little person that is half you. It's a miracle."

Their eyes drift back to the screen and Olivia feels like crying a little too. Elliot is right. This new little person is a miracle and she can't tear her eyes away. The doctor takes a few screenshots and measures the baby and then pulls the ultrasound stick away.

"Have you been feeling nauseous at all?" the Doctor asks

"Yes, I have. Usually in the mornings. Sometimes later in the day. But it never lasts long unless I see or smell blood."

Doctor Simmons' eyebrows shoot up but then she seems to remember.

"Oh, right. You're a Detective. Do you get into dangerous situations a lot?"

"Not anymore," she assures the doctor. "I'm not allowed to chase any bad guys for the time being."

"Good. Very good. Are you a Detective too, Mr. Stabler?"

"I am. I'm her partner," Elliot answers, and Olivia can hear a hint of pride in his voice. "I'll make sure she's safe."

Olivia rolls her eyes but bites back her comment that she can take care of herself. Elliot means well and it feels strangely reassuring to have someone look out for her.

…

Any ideas what could be bothering Elliot? Isn't he the sweetest best friend you could wish for?