Burning after Sex..?

Korin
My boyfriend and I have been having sex for about 8 months now and we've used a condom every time. Last month we had sex on my period and then it was a few weeks after that before we did again. I was on top (wasn't the first time I'd been on top tho) and it might have been one of the best times. But after that my vagina kind of.. Burned? Like it hurt a little at first and then when I peed it hurt too but it stopped after that. I blew it off because it'd been a while and so maybe I stretched back out, it didn't hurt during sex it just hurt after. We did again last night but it was quick and it hurt once again after I peed. He told me that it was just because we'd had good sex (I mean yea it was good but in 8 months it's never burned before...) Any clue as to what the problem may be? We've always used the same brand of condoms and it wasn't very rough either... Just to eliminate those possibilities.