Your saying slapping his hand off me- may mean he is either hitting your cercix or he is rubbing your clitoris very roughly with his penis. So if you adjust your posture hinting your b/f about clitoris and cervix.I wonder whether Kegel exercist will help you. You may google and try.It may help you in another way in making your pc muscle stronger and more flexible.
Try to find a position that u can get comfortable. I have found its better when he is behind and I was not a fan of this way before I got prego but its the only way it doesn't hurt or feel like he is hurting my belly
Me too!! It hurts so bad since I first got pregnant. My doctor said it's probably him hitting my cervix. Try different positions that he can't go in as deep, we can only do doggy style with my legs closed as much as possible to keep him from going in all the way