It has happened before on my old birth control, then I had a period every other week. Now on my new birth control, I've been on for about three months, I got my period on 1/7/15, spotting two days before I started, it ended on the 14th and for three days after I had brown discharge and started bleeding (my second period this month) on the 18th. Recently I have been getting on/off sharp pains near my belly button and mid abdomum area, I also had unprotected sex on one of the days I was spotting. I thought I had sovled the problem whenI switched birth control but here it is doing the same thing three months later..