You can have infection that does not show on the standard
test of nitrites but with the number of
epithelial cells /hpf 5- it is most likely not a clean catch, mid stream urine. I would suggest you redo the urine test and be very careful, it is hard to get a good "sterile" or as sterile as possible urine sample.
More importantly then the UA is the symptoms your experiencing that go along with a
the WBC. That will tell the doctro more about your clinical situation.