No feeling during sex?

I've been having this problem for over a month probably like 2 months now. When me and my fiance have sex it's feel absolutely nothing.. it has nothing to do with him he's always really hard I'm a little on the smaller side so I always feel him go in me.. he could be fucking the shit out of me and it don't feel good,I feel nothing I can't orgasm a lot of the times I fake it because I don't won't to make him feel bad.. what could be going on? In 24 weeks pregnant.. could that have something to do with it? I'm tired of not being about to enjoy sex😢😭😭