Sex burns and hurts after

Okay so this has never happened before but I had sex with my boyfriend yesterday and it burned while we were having sex and it wasn't pleasurable. After intercourse it burned for some time and then it started to hurt. The pain goes away after about 10 minutes but then it comes back every time I have intercourse. We have been sexually active for a while and this has never happened before. I don't have any sypmtoms of a yeast infection but the burning while having intercourse. Someone please help