Asymptomatic UTI often leads to pyelonephritis in pregnant women, and can also to growth retardation and low birth weight in their infants. That's why pregnant women are routinely screened and treated for asymptomatic UTI. Cranberry juice is helpful in reducing the risk of getting a UTI but not for treating a UTI. (I recommend pills instead of the juice.) AZO helps for pain but does not treat a UTI, so it will not prevent complications.
So while I'm not a big fan of antibiotics in general (eg, no, one does not need a antibiotic when one is congested and has a cough for 3 days!!!), I would follow your provider's advice and take the antibiotics. And probiotics for your gut.
Il faut vivre et non pas seulement exister.