My 3 year old son was just diagnosed with a bladder infection. The doctor informed me that this is not common and because of it, if the urine test came back positive (which he was 99% sure it would) he will need further testing. He mentioned a high white cell count. I asked if this was something I needed to worry about. He said that we should just wait and see right now. The clinic was extremely busy and I felt as though he was rushing a bit so I did not feel comfortable to ask any more questions. What does this mean? What type of "illness" or concern could this doctor have?