Daughter 20 Yrs. Old Has Had An Urgent Need To

daughter 20 yrs. old has had an urgent need to pee the last week, started on AZO 2 days ago. I sent her to an instacare today and they did a urine test which they say was within normal limits, so didn't treat her. She had in the last few days pain peeing, and smelly urine. She has seen the symptoms decrease today. They will be culturing the sample