why am I bleedin durin sex?
Sounds to me like some tissue was torn.
This tends to happen if your 'downstairs' wasn't moist enough before having sex, or he stuck it all in too quickly. So you need to tell him to make it moist before sticking his magic stick in, and be sure to take it really slow at the begining so nothing else gets torn. If this continues to happen, I suggest buying some lube to help yeah out.
Torn tissue can also be caused by having rough sex by the way, I'm sure the lube will help you out with that too.
if this is not the first time you have had sex I would go see your g.p. you might have some sort of infection down there. if it si your first time of one of your few times then maybe your hymen only just broke ??