I Have Small Patches Of Very Small Itchless Slightly Raised

I have small patches of very small itchless slightly raised bumps. similar to a rash but without the itching. There is nothing inside of any of the bumps (fluid, pus, etc.) I had sex with my girlfriend the night before the rash broke out and I had to pull a 12 hr shift at work without the chance to properly clean myself off for an extended period of time.