I don’t know how to title this

So my boyfriend and I are having a baby ! Due in Nov. I’m in my second trimester and for some reason I’ve been more emotional this trimester than the first. Anyway, he already has a little girl, the age of 3. I’ve not been feeling so connected with her during my pregnancy, and I do feel horrible about it.. but I also now haven’t been liking when my Bf brings her birth story or how she was as a baby.. i feel like I’m being compared.. I know it sounds horrible and i feel bad for feeling this way. But I’m not choosing to feel this way at all, cause I love her I just feel so distant with her, since she doesn’t interact with my pregnancy as my 3 year old cousin or his baby sister (4) and nephew ( 3) who love talking about my baby and touching my belly and interact way more than her.. He doesn’t understand that I’m not trying to feel this way, or try to get a certain way when he brings it up… I shut down and in my head I start saying “ I don’t really want to hear about this right now.” I’ve already tried talking to him about it to see maybe if he understands but now he just thinks I hate her.. but he already has the mind set that everyone hates her. I don’t know what to do or how to feel anymore. And I hate feeling like this cause I know it can effect the baby. Any suggestions or advice? ⚠️⚠️*****Now that we had this conversation it’s going to be harder to ask for him if it could just be me and him for my birthday, since he only has her on the weekends and my birthday lands on a Saturday.. since we never have the chance for alone time :( he works out of state most of the time and I stay with my parents when he’s gone, so I don’t feel alone.. I just want to spend some time with him.. how could I ask him this without it sounding bad ? **** ⚠️⚠️