Ive been having brownish discharge for 6 days past period what could it be? i had intercourse day before period started have pains now in area

See a doctor: The combination of abnormal vaginal discharge plus pelvic or low abdominal pain is worrisome for pelvic inflammatory disease (PID), the most common serious complication of STDs -- usually chlamydia or gonorrhea. These are more or less likely depending on your sexual lifestyle and exposures. See a doctor soon; if the pain is bad or if you also have fever, don't delay even though it's a weekend.