Okay yesterday I woke up and had heavy menstrual bleeding. There was some clotting it looked like, but that's not too unusual for me. Anyway day went on and already through it my period seemed to be almost gone. Now today, nothing. Any ideas as to whats going on? Only thing I can think if was I took 2 plan Bs in 1 week-used a condom (so it was protected sex) Im just a paranoid person so took it to be sure. The period I had before this one was a week late but 4 negative pregnancy tests and gyno says I'm probably not pregnant. Just started first birthcontrol pill yesterday. Could the plan B, birth control pill, or messed up period from last time be causing this one day period?