I have a uti. id like to wait to treat it. how long can i wait? is there any danger of spreading?

Don't wait: While some women can clear UTIs by aggressively increasing their fluid intake, many simply won't go away on their own and can certainly progress upwards into kidney infections (pyelonephritis) and/or enter the bloodstream (i.e., sepsis). Best to get your urine checked and to start on antibiotics.

Why wait???: UTIs often clear up without treatment, but not always, and there always is risk of complications like pyelonephritis or renal abscess (infection or abscess in the kidney), and of sepsis which sometimes is fatal. And why put up with symptoms? If you're worried about taking an antibiotic, that's nonsense. Risk from antibiotics is far lower than risk of bad outcome from the infection.