You could not have acquired any STD from the exposures you describe. If you really had urethritis, you caught it somewhere else. You have been directly evaluated by 2 health care providers, and no online source can provide more accurate information just by your verbal description. I see no reason to suspect your doctors are wrong. Anxiety probably is the most likely explanation for your pain; certainly no STD causes that sort of symptom.
Follow up with one or the other of your doctors if your symptoms persist or you otherwise remain concerned.
Good luck-- HHH, MD