Im 18 and I had unprotected sex last weekend in a lake. A few days later I started itching really bad down there and I noticed a thick cottage cheese like discharge. I have gotten treatment for a yeast infection cause that's what it looks and feels like (I've had them before). I used the treatment yesterday. And today the discharge was like a really thick yellow color. There is no odor. Could the yellow discharge be the medicine? Cause I asked my mom and she said it could be some kind of STD. I've been doing research and I haven't seen any std's that look or match yeast infections let alone my symptoms.