heavy bleeding foreplayPLEASEHELP

As recently as 2 days ago, my boyfriend came from from a trip where he had been gone for almost 2 months. We were so excited to see eachother, and we had sex alot in 2 days. Anyways, we went out with his friends and had some drinks, and ended up getting quite drunk. We got back to my house, and he started to finger bang me. We got REALLY into it, I was in no pain whatsoever, and he was trying to get to my G Spot. So about 10 minutes in, I thought for sure that I had actually ejaculated, and this would have been my first time. He thought so too, and then we looked down and their was actually so much blood that it looked like a murder scene. Like it completely ruined my sheets, it was all over the both of us, and it continued untill the morning and stopped at around 8 or 9 am.
This has happened a couple times, only during drunk sex though. Im 18, hes 19. We also used lube, but Im thinking maybe not enough. The only thing that confuses me is that I felt no pain at all, in fact I would of said it was my best orgasm yet. And he also keeps his nails well trimmed.
If anybody could help me or give any advice it would be greatly appreciated, as I was (and still am) very concerned and Ive read about a certain condition that targets girls who have sex under the age of 18 and experience bleeding after sex, and it usually leads to cervical cancer.