ok well in the past week, ive noticed that when I masturbate, a more watery discharge than normal comes, and its a dark brown bloodish color. And the past couple days, it comes during the day and I find it on my underwear. Its not alot, but it still concerns me greatly. I am 13 years of age, never had any form of sexual intercourse or relations, and I got off my period completely about a week ok. What could be wrong? It couldnt be a STD could it? Or Yeast infection? please help.