Elvis had the same problem, something to do with his mother
I’m 25 weeks along and my husband hasn’t stopped being intimate with me, but I will say he is definitely way way more gentle and it’s not our usual sex. He knows my back and hips are hurting a lot now so he tries to get me in comfortable positions and he doesn’t make it last long so I don’t get uncomfortable. A lot of times he will flip me on my knees maybe that so he can focus on my A$$ instead of belly 
But it works.
My husband was the same way. It’s frustrating sometimes, but normal