Last Friday ,I had unprotected sex with my boyfriend and he came inside of me then we continued for about 30 minutes. I'm currently on the depo provera birth control shot and I have been for about nine months now. Once I got on the shot, it stopped my period completely but two days ago I started bleeding very lightly and I had light cramps. I did some research and I believe it's implantation bleeding because it only lasted for two days and it been nine days since we had sex. I'm going to the doctor next week to find out if I'm pregnant!