Fiancé doesn't want sex?

I'm 21 weeks pregnant and I can't seem to get my fiancé to have sex with me recently. For the past few weeks, it's hurt me when I tried to have sex but the past two or three times I have I was fine and there wasn't any discomfort or anything. The past week or so I just can not seem to get my fiancé to want to have sex with me. He says it's because he doesn't want to hurt me but he didn't have a problem with stopping if it hurt before. I can't help but feel like he just isn't attracted to me anymore because I'm bigger now and a little more sensitive. It really hurts my heart honestly because we have sex almost every single day but now I couldn't even beg him for sex. Makes me feel like garbage fr.