Pain during sex??

i'm 15 weeks pregnant. I had sex earlier in the day today, and it was great. I was fine. But then, just an hour ago, it hurt me so bad I couldn't even do it.. It's like I can feel it in my stomach.. I was so mad I couldn't enjoy it. Misionary and doggy style are my favorite and it's like every way I did hurt my stomach. Towards the end, he said it felt like he was poking something... Why did it hurt? He did go pretty rough earlier today... anything I can to not make it hurt??