Okay so I'm 16 and since October 09 I've only had 3 periods. My first one being in October, this was normal. My next period was in February, this period lasted about 10-12 days but it just seemed like a brownish heavy discharge. My last period was in May and yet again lasted about 10-12 days. This again was just like a brown discharge. In between these months my discharge has sometimes been a yellowy/browny discharge & sometimes I get streaky blood in it (this lasts about 3-4 days at a time). I have had a lot of stress because of exams, so I thought I might just let it pass until they are over but there has been no change. I do have regular sex with my boyfriend (he is the only person I have had sex with) and have done for the past year and a half. I am almost certain I could not have any form of STD and have taken many pregnancy tests. Please help as I am so young I don't want it to be anything serious & if it is I would like to get it checked as soon as. Thanks, Charlie.