My girlfriend had her period Jan. 20, and it ended on the 24th. She says that it was just like any other she has had. We had sex on the 30th (today) and she had some bleeding afterward. In her terms "red with some brown, and then mostly red."

This struck us as odd, since her period ended a week ago. She is on birth control, I ALWAYS use a condom, they've never broken, and I pull out just before orgasm. We don't see how this could be pregnancy, but things I've read similar to this point to pregnancy.

To be honest, we're confused! What could this be?