Aww mama, I totally get why you're worried, that's such a tough situation para sa ganong edad. A few of us mums have gone through UTI scares with our boys, and honestly the antibiotic route first makes sense kasi sometimes the swelling from infection can look like phimosis, so give the meds a chance to work and observe muna as your pedia said. Once the infection clears, you'll have a clearer picture if it's really phimosis or just inflammation from the UTI, so don't stress about the circumcision decision right now, you can always get a second opinion from another pedia or urologist if you want peace of mind. Fingers crossed the antibiotics work and your little guy feels better soon!