I am on the depo shot, and have had a very bad experience on it, but the most recent thing is concerning me a little bit more, Me and my boyfriend had sex sunday night and I woke up monday morning and i was bleeding. It only lasted about 20 minutes and was rather light, but today (tuesday) I am having very severe mood swings. This was not my first time ever having sex. Can anyone help me figure out if somthing is wrong?