Pains in kidney area?

hi, I have been having pains in the kidney area of my back for about a month. The doctor tested my uring and there is an infection and blood in it. I feel tied in the afternoon and the pains are worse in the morning. A couple of months ago I was having a sharp pain in my left side when urinating but this has now gone. I have just had an ultra sound of my abdominal organs and was tols all was in order. I have been on anti-biotics but it hasnt helped....What could this be?