I began having left flank pain, frequent urination, nausea, and low grade temperature 4 days go. Urinalysis showed small amount of wbc's, rbc's but urine culture was negative. CT scan showed an "11mm structure in the left kidney which could be a cyst or a renal carbuncle (small pocket of pus) and an asymmetrical prominent rim also enhancing the focus of the left kidney" (whatever all of that means). I was given an IM injection of rocephin and began taking cipro. My physician doesn't seem to think that I have a kidney infection because my urine culture was negative (is this possible?). My symptoms have not improved and I am beginning to feel like my doctor thinks I am "crazy". What should I do next?