what could be the problem?

Jozzlin

today is the 3rd day of my period (out of usually 7) and on the first day i had a pretty light flow but not light enough for a panty liner on my second day it got a little lighter and it was red mixed with light brown today im only bleeding a little bit with small amounts of brown i had unprotected sex last night and a few days before my period started (he came inside) could that have anything to do with why my period is being so weird?