Kidney Infection?

I was diagnosed the other day with a UTI. The Dr prescribed a 100mg antibiotic twice a day. Today there is a horrible pain in the right side under my rib, pelvic area, and on my side/back so I think it may have spread to my kidneys. This is my first time experiencing a UTI... any one with experience, would you recommend going to an urgent care since my Dr doesn’t open until Monday... or waiting out the antibiotics and see if it gets better? Or am I okay to wait until Monday to call the Dr? Just not sure how serious this can be.

Any advice appreciated 💕