Sometimes the nerves can become irritated and will continue to produce the urgency feeling even when tests return as clear. Doxy or Cipro never worked for me for a UTI, perhaps you need to try a different medication. I would only respond to amoxicillin which is not the norm, but worked like a charm.
Try flushing out your system with lots of water, cranberry juice as well. You may have UTI or at least need to be treated for one.
Yes. I have had a urine culture. Nothing found. Had prostate checked. Doc said it felt normal.
Were you checked for a urinary tract infection? Those are caused by e.coli bacteria found the colon. They can spread to your bladder and other areas and from my experience are horribly painful and cause you to feel like you have to urinate constantly.