Std? Help please

Hey long story short I made the dumb decision to go to a massage parlor. She offered extras which was a blowjob and sex with a condom on. The whole encounter was only 5 minutes and I showered and peed right after. She was very adamant on wearing a condom which I agreed right away. she only works once a week.

Fast forward 3 days and I have no symptoms or anything besides a rash that isnt anywhere near the penis. Its In-between the leg and thigh. It does hurt a bit but I've had these before when my underwear will chaf or when I shave or it's warm out. I shaved the day before I went so I'm wondering if it could just be a rash or something? My doctors appointment isn't for 4 weeks and living with this anxiety sucks.