Welcome to Healthcare Magic,
Sometime due to different factors( stress
, physical activity, nutrition, emotional factors, etc.. ) periods can delay or come early. Possible your brown discharge is correlated with upcoming periods, if you exclude such condition then your sings suggestive for bacterial vaginosis
and you need laboratory exam with culture, urine analysis and transvaginal ultrasonography
( check uterine cavity
to rule out polyps that also can bleed). Until you will clarify , avoid intercourse and maintain adequate hygiene.
I wish you good luck and speedy recovery.
Hope this helps and I have answered your query. If you have additional queries don’t hesitate to ask.