Sex and pregnant???

Amber
I'm 36 weeks and 2 days. My fiancé and I are worried to have Sex because every time we finish having sex I have this weird feeling in my belly, like I'm getting sick to my stomach. And sometimes after sex I get really bad contraction/brackstin hicks. Does anyone else feel like that? What should I do? My sex drive is really high since my third trimester can that mean something wrong?