i have recently had unprotected anal sex with an unknown female, a few days later had stinging pain when urinating and pain in the lower pelvic area. had a blood and urine test exactly one week later, was clear of any STI s at this stage, 11 days later a small pimply rash appeared on my penis, scattered and not too many, they weeped only once after a shower, kept them dry with powder, they are still there to see but healed straight away, never crusted over or scabbed! a little itchy but unsure what it is......? help please...?