Until recently there was not much scientific evidence to help answer your question. We know that approximately 20% of women will experience a urinary tract infection
(UTI) during their life, and of these women one-fifth will have a second or more infection in their lifetime. Pregnant women are even more likely to develop UTIs. As prevalent as UTIs are today, there is little reason to believe that in the time before antibiotics they were less so. Consequently, anyone with a UTI had to clear the infection without antibiotics by necessity.
Our human immune system evolved without the aid of antibiotics and is quite effective. In fact, many antibiotics do not actually destroy bacteria, but rather halt their ability to grow giving time for the immune system to work at clearing the infection. For simple infections antibiotics most likely speed the time to recovery and decrease the likelihood of complications, but may not be necessary to actually cure them. To test this idea researchers in Germany randomized eighty women with UTI symptoms without evidence of complications to either three days of symptom control with ibuprofen or the antibiotic ciprofloxacin. The results of this small study suggested that ibuprofen was no worse than the antibiotic at treating the UTIs. So while this is just one, relatively small study, it suggests that antibiotics are not required for most women. Still, I suggest contacting your primary care physician
who can evaluate your symptoms and help direct you to the appropriate therapy. Good luck!