Ratchet is overprotective of (Y/N), which leads her afraid to tell him about abdominal pain until it's life-threatening.

(Y/N)'s P.O.V.
It's been interesting being friends with the Autobots. Add I've fallen for one, and now we're married, or as they call it, sparkmates. Even when we were dating, Ratchet was a little overprotective. I should be lucky he didn't limit our dates to in the base. Nor did he forbid me from going on missions — until two months ago. I love Ratchet, but this is scrap.

I try to talk to him, but this doesn't go well.
"ABSOLUTELY NOT!" Ratchet argues.
"But Ratchet—."
"But you forget Soundwave almost got you. If Bulkhead didn't stop him in time. What if he tries again? Or you get hurt?"
I know he's worried, even friends would worry, but this is ridiculous.

Ratchet's P.O.V.
I watch (Y/N) run to our berthroom and close the door.
"Ratchet, you know this isn't healthy. You're treating your sparkmate as a prisoner," Optimus argues, "I will personally protect her."
"Fine," I sigh and go to my berthroom.

I activate my holoform and get on the berth. It's clear (Y/N) has been crying. I kiss her and move her close to me.
"I'm sorry I've been overprotective. I love you and am scared to lose you."
She rolls over and kisses me. She doesn't look good and feels a little warn. (Y/N) claims it's from the crying, but I don't think so. She won't tell me anything else either.

(Y/N)'s P.O.V.
Waking up at two in the morning with terrible pain is not great, and if Ratchet finds out. I need more pain relief; it's the only way I've been keeping this from Ratchet the last thirty-six hours. I try to get up to go into the bathroom but fall to the floor. Fuck, now it's an emergency. , But it hurts to even breathe.
"(Y/N)!" I hear Ratchet scream as he sits on his knees next to me, "what's wrong?"
"My stomach; it's been hurting the past two days. I was trying to get more pain relief."
"You're burning up!"
Ratchet picks me up, which adds to the pain, and I scream.

Optimus Prime's P.O.V
Hearing screams at two in the morning could mean the kids are watching scary movies, but they're not sleeping here tonight. As I rush out of my room, I catch Ratchet's holoform carrying (Y/N) down to the medbay. I activate my holoform and follow him. I stand by the doors, watching Ratchet panic as he examines his sparkmate. Something is definitely wrong looking at (Y/N)'s abdomen when he lifts her shirt.

"I have to do this," he says, regretting the pain he's about to cause and how he should have brought her here in his bipedal form. This could be serious, and the thirty seconds could make a difference between helping (Y/N) and watching her die. I close the door — though it's not going to make a difference — as Ratchet puts the transducer on (Y/N)'s abdomen. I rush to the bed, knowing I'm going to have to hold her down. Not even thirty seconds pass before I see the concern on Ratchet's face.
"This is an emergency; I have to remove her appendix now," he tells me
"You can do this, Ratchet," I tell him before leaving the medbay.
I know he's worried about how this is his sparkmate he has to operate on.

The others are waiting in the hallway, worried about why (Y/N) is screaming. I wish the screaming was because (Y/N) was pregnant and just had the baby; at least there's a happy ending. This is serious, and Ratchet could be too late. I dread telling them what happened, but I can't simply say Ratchet has it under control.
" ...the kids are not to come here until further notice," I finish and go call Fowler — who's not going to like being woken up this early.
While he's half asleep, Fowler is concerned about the situation. He tells me he can call June to get whatever we need from the hospital and tell him how things go.

Meanwhile

Ratchet's P.O.V.
This is scary; needing to do an operation like this on my sparkmate. There's no time to get (Y/N) to the hospital; add how she's scared as it is, so to have someone else take care of her would terrify her. She's terrified she won't wake up. I don't think it's anesthesia fear, but knowing how serious this is. I hold her hand as she goes to sleep.
It's scary seeing how close (Y/N)'s appendix is close to rupturing, how close I was to watching her die. This surgery takes an hour; I figured Optimus would have gone back to sleep since there's nothing he can do to help (Y/N).

I'm glad (Y/N) woke up soon after I finished, but went back to sleep as she's still feeling tired. I didn't think Optimus would be up three hours later. He worries about seeing (Y/N) asleep.
"She'll be ok; she's just tired," I explain.
"The mission is on hold until she recovers," Prime tells me and leaves the room. He'll argue I should still let (Y/N) go on missions even though she tried to hide a life-threatening issue. Though I know, I'm the one who made her think she had to hide the pain. All I want to do is protect my sparkmate. I don't know if I'll ever find the balance between protection and treating her like a prisoner without Prime lecturing me. One day this could be something more serious, and it'll be my fault.