As your period is delayed, you should do a Urine Pregancy Test to find out if you are pregnant. As you have a previous history of STDs, I would suggest you to get tested for recurrence of STDs. Brown discharge and delay of periods can also be due to recurrence of STDs like HIV
,Gonorhea. STDs have adverse effect on the fetus if you are pregnant. So it is essential to rule out pregnancy
and get treated for STDs if you test positive.