Hi, I have had a few UTIs before, I recently had one and the doctor gave me Zinnat to clear it up. It took 15 days to show that there are no white blood cells in my urine but he said now he's seeing blood but I had my period while i took that test. He said come back to do another lab test. I feel frustrated because I still have the urge to urinate, my pelvic region and lower back aches but not severely and I feel like something is blocking my urine from passing or something needs to come out.