itchy

I'm kinda have an issue I'm 16 and I have an itchy area... I had sex for the first time but I feel as if this is just abrations from it because now it itches in my vaginal and rectal area I got blood work for STD and HIV but I'm still scared... is it nothing ?  
Could it be something worse it's been going on for at least 3 days and i don't know what to do I've tried everything to soothe the itch and still is in this condition