bleeding during sex

Okay so I lost my virginity the same time last year with my ex boyfriend and we had sex a lot. I never bled once during or after sex then... but today with my current boyfriend we had sex for the first time (I haven't had sex in 10 months). And I bled during intercourse and I still am a little bit hours later. I'm just worried because this didn't happen when I lost my virginity so I don't know why it is now..