Oh, I know too well how you feel. If you don't start feeling better soon, call your doctor. They can run an additional test on your sample to see which antibiotics it will respond to. I'm allergic to sulfa, which was the main UTI medicine until some new antibiotics were invented recently, and I can't tell you how many times the doctor put me on one antibiotic and found out 2 days later when the culture came back that it wouldn't work. Not fun.
Feel better soon. {{{Hugs}}}