UTI? Yeast infection? STD?

soooo I recently had unprotected sex for the first time with someone and the next day I was fine, then the day after that I had burning sensation when I peed I immediately went in to get tested. I tested positive for a UTI and got antibiotics for it. But then a couple days later I had no other symptoms but a really bad itch feeling on the opening of my vag.. I don’t have any weird discharge and it smells completely normal, it’s not a weird color or anything although it’s a little thick. Anyone tell me what this could be????