I recently went on Birth Control about 3 months ago. Approximately a month and a half ago I kept taking my pill for the week I was supposed to get my period so my boyfriend and I could have sex. After that I bled for 2 straight weeks, but I thought it was just my body reacting to what I'd done with the pills. Everything stopped and my body was back to normal for the past few weeks. Now though, everytime we have sex, I bleed a little for 1 or 2 days after. Why is this?