i am 18 years old i've had my period last sept10 evening... i've had an intercourse with my bf sept21 around 1 am... after that, morning i noticed some fresh blood coming out of me and until today sept 22 it still there... i wonder what it is... i've had a 28-day cycle for last 4 months.. what could this possibly be... i hope u can post a reply as soon as possible