Nervous from not treating uti

Cass • Expecting baby #1 🎀

So past few days I’ve been having a lot of lower back pain and I’m pretty sure it was actually my kidneys. Got antibiotic yesterday for bacterial infection but still felt terrible today so called and went to do a urine culture and doctor now thinks I have a uti and prescribes another antibiotic. Turns out they neglected to tell me I had bacteria in my last urine culture and now I’m terrified I’ve had a uti for months and haven’t had treatment (was having lots of Braxton Hicks also so even more scared )

Does anyone know how long an untreated uti can go before it hurts baby or puts you at risk for preterm birth?