So my vagina really itches and using a hand mirror its really red down there. It burns and itches randomly throughout the day and I'm a little worried. The vaginal fluid is brown and looks a bit like phlegm. I know its really gross but I need help! This started happening a couple days ago, after i got off my period. I mean I'm sexually active and had sex for the first time while on my period and was wondering if that could play a part? also what causes urinary tract or yeast infections, and how do i prevent them?