Well that is good news! The improvement in fibromyalgia symptoms could be due to the fact that you must be getting some pain killer, the after effect of anesthesia and due to the fact that you must be taking more rest than you normally do. Take care!
The medical advice given should not be considered a substitute for medical care provided by a doctor who can examine you. The advice may not be completely correct for you as the doctor cannot examine you and does not know your complete medical history. Hence this reply to your post should only be considered as a guiding line and you must consult your doctor at the earliest for your medical problem.