Redness on penis head

Im usually a very paranoid person, but id like to get some input on this before i completely freak out. I hooked up with a girl without protection 3 days ago and today noticed a red rash or something on the head of my penis. I have gotten small minor red bumps before that was balantis and went away but i cant remember if it looked like this. The girl said she got tested before hooking up with me and she was good so im not sure if im just being a paranoid mess or maybe she lied? please give me your input im planning on heading to the clinic tomorrow morning to get tested. It got more red the more i messed with it trying to get a better look btw image

try cleaning it properly.