Sexless 3rd Trimester??

I'm 36 weeks pregnant and my fiancé and I haven't had sex in almost 5 weeks. I'm beginning to think it won't happen until I'm fully healed 6-8 weeks AFTER THE BABY IS BORN?? It makes me sad and kind of hurts my feelings because he never comes on to me anymore, I genuinely feel like he's not interested in sex with me at this point. I haven't gained much weight this pregnancy, it's all in my belly. Everyone I know says if it wasn't for my belly I wouldn't look pregnant and I actually feel really great! I just don't understand why he doesn't seem to want me anymore the way he used to.. when I try to come on to him he has an excuse every time. I don't think he's cheating on me but I do think something is up.. has anyone else experienced this?