I had sex 3 days ago, when i wiped there was a little blood.for the past 2 days i've had brown discharge. i'm 1 week away from my period. no pain. ?

Infection? STD?: Any new, abnormal, or unexplained vaginal discharge should be medically evaluated, and so should any abnormal vaginal bleeding. You apparently have both, so see your doctor soon. At age 23, STDs (gonorrhea, chlamydia, trichomonas, etc) are among the common causes (of course only if at risk); or other infections, or perhaps cervical inflammation (cervicitis). Get it checked out soon. Good luck!