Nervous About Son's Tests

I have a 17 year old son that has severe clubbing of his fingers and toes.  After a long wait, I finally was able to get him into Chirldren's Hospital.  The dr started some base line testing on Monday.  On Wednesday, the dr. called to say that his CBC showed that he was amenic and his blood oxygen test came back at 93% a little low.  Also, his sweat test came back at 55 which is inconclusive. The dr wants to do more testing on Friday.  In the meantime, my mind is going a million different directions.  Is it possible that he is positive for CF?  Any ideas are greatly appreciated.