Am I wrong?

My boyfriend and I have been together for 2.5 years. We’ve always been very open with each other, and we don’t keep secrets from one another. I’ve always been the “chill girlfriend” that doesn’t mind if he has friends of the opposite sex because I’m a slightly normal human being. I’m 5 weeks pregnant today, and I stumbled across a message that he responded to from my phone because his is broken at the moment.

This girl had posted on her ig story about “what trader joe food are you?” Or something similar. It landed on buffalo wings, and he responded “yum.” To which she said, “I’m a snack,” and he replies “yes indeed.” I’m sure I’m just overreacting. But since I’ve gotten pregnant, I’ve been sooo sensitive about him paying attention to other women. I already struggle with the fact that his baby mama is still in his life far too much for my liking. She doesn’t even see their child, but he still just talks to her. Has her name as some nickname on his Messenger still. I just want him to give me the most attention for once, considering I’m the woman who essentially saved his life when he was in an abusive relationship. I’ve sacrificed so much, and all I get is him messaging random friends instead of talking to me.