I tested negative for sti, but still have an itchy urethra and painless rashes on my penile?

Contact allergy: Good you've tested negative for a sexually transmitted disease (STD), but given you still have a problem, the doctors should seek out the cause. I wonder if you might have a contact allergy - perhaps to a new detergent, latex condoms or some other chemical or compound. If you show the rashes to a doctor, you hopefully can get some answers and then a plan to take care of the problem.