I'm 21yrs of age.. "DNT USE BC" started my period Aug.19.09 had unpretected sex during the ending of my period, on Aug.23 (they usually last 8days but this one only last 7days) no bleeding during the time of sex. Ending exactly on Aug.25 on Aug.27th had sex w/ my partner in the A.m., around noon I had slight cramping not nothing major on my lower right abdomin. On Aug.28 after sex had a brownish-redish discharge, later agin that nite went too use the restroom whiped n had clear discharge w/ a small strain of blood was present not alot just a tiny amount "normal color not brown" but now still Aug.28th no signs of it anymore.. but I had a little cramping did'nt last long at all. What could this be? Can this be old blood from my menstrual? This never happend to me befor.