bruised!??

my bf and I tend to go pretty rough sometimes when we're having sex and most of the time I can handle it and everything is fine but the other day we were going at it and I had a pretty intense orgasm and then he like hit a bone? muscle? right near my belly button or like right under it and it HURT. it felt like he hit something pretty hard and then after that my stomach felt like it had a bruise but like in the inside. it was pretty tender and didn't go away for awhile but then it eventually got better but like I couldn't really walk right or anything or sit up because it was hurting me.... what happened has anyone had this before?? any help would be really appreciated!!!