What Could Brown Discharge Instead Of Period Denote?

OK MY PEROID HASNT BEEN ON SINCE LIKE A MONTH NOW. I HAD STARTED TAKING BIRTH CONTROL PILLS THE BEGINING OF MAY BUT REALLY WASNT TAKING IT LIKE I WAS SUPPOSE TO. MAY 30 HAD MY REGULAR PERIOD HAD SEX WITHOUT A CONDOM ON THAT SAME DAY, PERIOD LASTED A WEEK, WENT OFF A DAY CAME BACK ON A WEEK WITH BROWNISH REDISH KINDA DISCHARGE. THEN LIKE SECOND WEEK IN JULY I WIPE MYSELF ONE TIME THERE WAS BLOOD SECOND TIME NO BLOOD. 4TH WEEK IT WAS PINK DISCHARGE STUFF NOW ITS THE BROWNISH REDISH STUFF AGAIN. WHATS WRONG