You don't say how old you are, but I'm surprised your doc didn't send you to a urologist.
Hard to say, you’ll need to keep seeing Dr’s, perhaps more tests. There’s also smthg called ‘NSU’ = Non-Specific Urethritis, meaning it’s not Gonorrhea or Clamidia, but some other organism. There’s also a slight possibility of a prostate infection, but I think that’s less likely. Either your reg Dr or a Urologist should check the prostate just in case. If your reg Doc can’t get to the bottom of it, ask for a referral to a good Urologist. Good luck & let us know what’s found…