7 year old with leg pain swelling and high WBC

My 7 year old son awoke a week ago complaining on ankle pain in his left leg.  The pain spread over the week to his left knee (which he sprained in January and healed).  The knee became swollen and tender to the touch.  He spiked a slight fever on the third day.  X-rays are normal.  But his CBC came back and the hospital said his normal blood count should be 14 and it is 14.8.  This is the 3rd time in 8 months his count is elevated, and the first time it was double the normal amount.  The blood test was taken 6 days after the intial symptoms so not sure how high it actually got.  No answers as to the cause. Now he is complaining that his knee feels like it is "asleep" and if he attempts to put his foot flat he loses his balance and his knee buckles.  Can't get to pediatrician for another week.  Hospital running Titer waiting for results.  I am becoming very concerned.  His cousin was diagnosed with Lukemia at this age.  Is there something I am not doing that I should??? Or something I should suggest they look at?  PLEASE HELP ME!!!!!!!!

[Dallasfan]

Take him to your local Pediatric hospital. He needs a orthopedic evaluation. A similar case in our clinic proved to be bone infection. It could be other things. I won`t speculate further

[squishy1108]

Thank you for the help.  As of right now he tested positive for lymes so treating that is step one.  Thank you for the advice