Welcome to HCM,
You are having UTI,and was prescribed Augmentin
which is antibiotic given to clear infection but many times Urine culture and sensitivity test is done which grows the organism and tests which drug is most effective in treating the infection is in question.
In UTI Gram negative organisms are commonly grown is E.Coli
After culture and sensitivity report antibiotic needs to be changed according to report and Nitrofurantoin
is good oral antibiotic for organism causing infection.
I am sure this clarify your doubt and please take lot of fluids.
wish you speedy recovery.