I am sorry to hear that you are having different investigations.
It is very difficult without being involved in your care to know why you are having a scan.
GP's have guidelines as to when different tests are organised. When a blood count is abnormal the GP needs to find out the cause. I am not sure why you went to the GP in the first place? A white blood count can be raised for different reasons including when an infection is present.
You could see if you could get a call back from the GP to find out why you are having the scan if you would like to find out more.
The NHS have written a useful guide on things to ask your doctor which you can see here
