Two urine tests that had wbc but negative for infection. what could be the reason for the wbc's?

Many possibilities: Some infections don't show by standard urine culture. Gonorrhea, chlamydia, and other STDs, if at risk for STD. Other non-STD vaginal infections. Inflammation of the cervix (cervicitis). Less commonly, kidney disease not due to infection. Finally, even a UTI caused by uncommon bacteria that are hard to find by culture. Symptoms you have may help give clues. Discuss with your doctor.