Aaaaaaah...what a perception your doc. has about fibro. I would find a new doc if I were in your shoes.
There're many, many overlapping symptoms that fibro and me/cfs shares.
I don't believe there's one definate blood test for me/cfs....what specific tests are good indicators of your having me/cfs escaped me for the moment. Will try and gathere them and get back to you if no one else will come up with an answer.
Hang in there.
I agree with kitonthemoon. If you get frustrated with your physician, consider googling, "Co Cure's Good Doctor List" and find a physician in your area who frequently diagnoses and treats both fibro and CFS.