I wouldn't try to treat a UTI on your own, especially not while pregnant. Any infection can be really bad for both you and baby during pregnancy, but especially an infection capable of spreading to your kidneys and beyond.
I have only tried natural remedies for a UTI one time, about a decade ago, and I would never do it again, and definitely not while pregnant. Two days into the natural remedies (a strong herbal tea, cranberry juice, garlic, tons of water), I was curled up on the couch with a high fever and back pain. I had no idea what was going on. A friend took me to the hospital where they discovered that I had sepsis. The UTI had spread to my kidneys, and I was very ill. I was lucky that I didn't suffer permanent damage to my kidneys.
During pregnancy when I have even the slightest UTI symptoms I have always gone to see the doctor and 2/3 times it actually ended up not being a UTI, something else was causing the pain while urinating, so the doctors took no action. I'm still glad I went in those two times though, because I'd rather have 1000 false alarms than have a infection go septic again. The one time that it was confirmed as a UTI, I took antibiotics and it cleared up very quickly with no ill effects on DS.