What preparation are you using exactly? Vagifem or something else? And have you been using it daily for 3 weeks or less often. Usually there is a loading dose of daily and then twice a week, but for some women that is not enough.
Another option: during my last pregnancy, I did have a UTI, but after the antibiotics, I also just kept having a burning sensation when peeing. This turned out to be a fungal infection (I didn’t have many other symptoms beside the burn, unlike a previous fungal infection way back when) that needed constant treatment until the end of my pregnancy, and then it resolved (hormones during pregnancy make you much more susceptible). I think some women in perimenopause do get more fungal infections due to changing hormones. Can’t hurt to try a treatment for it yourself. During my pregnancy, I had a test, because my dr wanted to rule out other types of infections and I definitely didn't recognize it as a fungal infection.