My fiancé and I had unprotected sex multiple times March 1st and 2nd. I was supposed to get my period March 27. But instead I'm having brown discharge when I wipe my pads don't even get full with it. I'm having a bit of cramps as well. Also a low back pain has started. The last time I had my period was February 21st it lasted till February 24th and it was pretty light.