What's wrong? Did I injury myself?

I'm 21, healthy, never had sex with a man, I normally masterbate. On Sunday, I did and everything was fine. On Tuesday, I went overboard, I did it three times in a row, I tend to clench up my stomach muscles because I have a long torso so I can handle the dildo properly. I do push and stick out my hips abit as it feels good when I do. I've never experience this before though. There was no blood on the dildo afterwards, my period was three weeks ago before this and even an hour after, there was none. Though a few hours later, I was bleeding heavily, no pain and with a few clots. There was no pain during the deed either. Then for the next three days it was very light, brown like old blood. It's only smell was copper. Everything is back to normal now. Did I injury myself? Start my period back up? My period usually lasts 4 days, but it goes med, heavy med, light.

I normally have normal periods and discharge. Nothing odd has happened before Tuesday.

I've been masturbating since I was 16, I will be having my first pap smear in the spring.


Sorry about the detail, I think if you explain everything, people have a better idea of what could be wrong.