My girfriend and I had sex and it is not our first time. She had her mensturation cycle a week ago and we had unprotected sex a day ago.I reoved my penis seconds before I felt I'm ejaculating. Now she says she is bleeding light again.what could be the reason?

First off, are you wanting to get pregnant. I know this is completely unrelated to your question, but I have to ask because pull out is the worst form of birth control EVER. You'll still get pregnant.

How rough are you guys and is she lubricated enough? Does this occur every time you have sex?

Very likely pregnancy. Pulling out seldom works, it only lowers sperm count, lots of sperm in the early fluids.

So now you wait and see if she gets next months period