I have been seeing brownish discharge in my underwear and i have not had my periode so does that mean?

See a doctor: Any new or unexplained vaginal dishcarge needs professional evaluation. There are many possible causes, but colored discharge -- yellow, green, "brownish", etc-- often means infection. Gonorrhea, chlamydia, or other STDs are possibilities if you are at risk, such as new partner recently, partner with others, etc. And since you selected STD as a topic tag, this seems to be on your mind. Good luck.