Dr. found white blood cells in urine under microscope. dip and culture tests normal. neg for infection or bac. ct scan was normal. no stones. ?

Several causes: Ok..White cells in your urine indicates your kidneys/ureters or bladder is inflamed. All inflammation does not necessarily mean bacterial infection. Viruses can cause this too. Now..A ct scan. A ct scan will only show "stones" if they are calcium or mineral based. Cholesterol stones will not show up like this. Interstitial cystitis can also be present exactly as you've described.