Newborn with a UTI

Anyone else have experience of a newborn with a UTI? My baby girl is 17 days old and has been diagnosed with a bad UTI and is in IV antibiotics for 3 days 3x a day and then a kidney scan Monday. She has no infections in her blood tests and is really well in her self and the UTI was found by 'accident' after routine tests for jaundice that hasn't gone yet (she is fully breastfed so that can prolong jaundice). I'm so worried and hate seeing her with a cannula in her tiny hand. Worried her scan may show something as well.