I have read before that inflammation and irritation can still be present even when the infection is gone. As you actually had a UTI only 3 weeks ago I would give yourself a bit more time to heal!Do you think? I had a UTI about 3 weeks ago and was prescribed a 3 day course of antibiotics, which cleared the problem, could this be happening that many weeks after the problem has gone?
If symptoms still persist after another week or two it could possibly be interstitial cystitis (it's not life threatening!)