randomly? So I've been sexually active for nearly 2 years now and just the other night I was having sex with my boyfriend and all of the sudden I started bleeding. I have been on the same birth control for almost 2 years and my periods are VERY reliable, and at the time I still had almost two weeks until it was time for my next period. The blood was BRIGHT red and there was no pain associated. I stopped bleeding immediately after we stopped. I know it can't be an STD because we've both been tested and we were both clean. My friend suggested maybe he could have "popped my cherry" which at first I thought was ridiculous but it definitely made me curious, because I can't really think of anything else that would cause this. Some opinions would be appreciated 