My period ended about a week ago and I'm bleeding again, it isn't a normal period bleeding, it's lighter. Any idea what could be wrong? I had sex about 3 to 4 days after my period ended; it was in my fertile window and we didn't use protection, but if I'm bleeding I can't be pregnant right? So that can't be it. Help?

It could be from irritation to your cervix from the recent sex. It could be due to ovulation. Pregnancy will certainly be a possibility, but wait and see what happens when you would expect your next period. I'm not quite sure if you are hoping to be pregnant or afraid that you could be pregnant.

Obviously, if you are not wanting to become pregnant at this time, do be sure to use appropriate birth control at all times to lessen the chance of an unplanned pregnancy.