OK the nurse in me has to ask..
Are you taking all of your antibiotics as prescribed?
Is the dr doing a culture and sensitivity on the urine so they know they are giving you the correct AB?
I had a UTI a year and half ago and I think it is because where I worked they were sitting the tp on the floor.
You have all of my sympathy. I would rather give birth than have a UTI. Also ask Your dr if you would benifit from cranberry capsules.
Good luck