it could be somethings as simple as a blater infection! Just hang in there and calm down!
First of all, without knowing what it is- you really need to calm down. You are working yourself up over something that could turn out to be nothing. At the moment you don't know anything so stop worrying over things you can't control.
If it was something that has the potential to be serious your doctor would have told you. All they are is doing a couple of tests at the moment.