sex has become hard!

Hey ladies I need a little advice here! I'm current 35 weeks and 1 day pregnant me and my husband have sex here and there. My Stomach is so huge and I love when he's on top but when he gets on top I feel like he's suffocating me and our unborn child lol. I feel bad because I try my best to keep having sex with him and I just haven't been in the mood. He also thinks having sex is good to dilate the cervix which I get but when we finish I'm in pain:/ and I'm already having horrible pelvic pains