26 years old f. i have bladder pain, burning when urination, frequent urination, and constant burn in the vaginal area i did urine culture, showed no bacterial growth. urinalysis showed wbc 40, rbc 12, abundant mucus, leukocytes +1, no bacteria?

Symptoms and urinalysis are consistent with acute cystitis but negative bacteria in urine smear and urine culture rule out bacterial infection. Viral cystitis can't be ruled out. You just need to drink fluid well for a urine output 2.5 liters a day for a couple days and take azo for pain if available. If symptoms recur in the near future with same urine findings, you should see a urologist.

Vaginitis can give similar symptoms. Drink plenty of water, keep vaginal area clean, avoid alcohol and constipation empty your bladder when you get the urge, repeat a midstream clean-catch urine test and if burning in vagina persists pl see your Gyn. Hope you feel better