Sex has stopped in my relationship

Firstly sorry about the long post. Here's just a bit of background to my story. I've been with my boyfriend for almost 3 years now and we've lived together for just over a year and a half. I'm 16 weeks pregnant which was a surprise but we're both happy and excited about welcoming our baby. We're financially stable and both have good jobs, so fortunately money hasn't been too much of a worry for us. I'm completely in love with my boyfriend and we get along really well, but recently we're not having sex anymore. There have probably been around 5 occasions where we've had sex since I've been pregnant. Our sex life used to be amazing and we would have sex regularly, I'd estimate on average 3 times a week, despite us both working full time and having busy schedules- this never seemed to affect anything. I haven't suffered any morning sickness or any other symptoms that would make me not want to have sex. I've spoken to my boyfriend and expressed that I'd like to have sex more etc and that I feel unattractive because he never initiates anything anymore and if I ever try to he rejects me. He just tries to make a joke out of it and says it's not a conscious decision to not have sex etc but I don't know what else I should do. I don't want to make him feel pressured but I just feel unwanted. He's never been the biggest fan of making out so we never even really kiss, we do cuddle but there's never anything remotely sexual recently. I just miss this part of our relationship and worry that things will only be worse once the baby comes. I don't feel good enough for him anymore. I have offered to give him oral sex on a few occasions and he's accepted and really enjoyed it, but then he doesn't do anything to me in return, which he always used to do without me even having to mention it. I've lightheartedly asked him if he's just been watching porn and he says he hasn't and I do believe him but I just can't understand why he seems to have no sex drive at all anymore 😩 is anybody in a similar situation who can relate? Thanks for reading 🙂