Considerable white cells in urine?

An infection would not necessarily show up in blood work if it is localized or mild. At this point, its a reasonable assumption that the problem might not be a UTI. There are many different things beside a UTI that can cause WBCs to show up in urine. Having a tender belly raises several possibilities if its related to the WBCs in the urine. The docs need to look more closely for an explanation. It might be worthwhile to have the docs run a urine culture and examine a stool sample and a vaginal swab for signs of an infection or parasites, and maybe and get an abdominal ultrasound. All of these tests might not be necessary, but together, these tests would screen for the majority of things that might cause abdominal tenderness and WBCs in the urine.