Something is wrong.

19 days ago I lost my virginity to my boyfriend and had sex with him twice after that. The last time we had sex we didn't have any lube so he just used spit. I had no symptoms at that point yet. A little less than a week later I started experiencing some itching. This was taking place during my period which started about two weeks ago (brown discharge for about a week and then blood for about a week). I am on birth control and my period wasn't supposed to start until today. Since last Friday I've been experiencing some itching and pain down there. I also have had light bleeding today that has been almost watery with little red chunks in it. The pain and itching is so aggravating and I am praying to god it isn't an std. My boyfriend has only had sex with one girl before but he said neither he nor she ever showed any symptoms of an std. I'm suspecting a yeast infection and the odd period activity just a result of sex changing up my cycle. Please say I'm right and this isn't something big.