Hi, welcome to the ehealth forum and I am glad to help you.
You seem concerned if the symptoms you have are of lupus and wrongly attributed to Fibromyalgia Syndrome.
Lupus is an autoimmune disease in which tissues and cells undergo damage mediated by tissue binding autoantibodies and it affects the various systems in the body. The diagnosis of lupus is based on clinical features and autoantibodies. Some criteria having 11 components have been devised which is commonly followed and if patient has any 4 of these during the course of disease, the diagnosis of SLE is likely but not definite of course.
ANA are positive in >95% of patients during the course of illness but if you get repeated negative tests, it suggests that the diagnosis is not SLE. ANA negative lupus exists but is very rare and is usually associated with other autoantibodies (anti-Ro or anti-DNA).
You can get ANA repeated and keep follow up with your rheumatologist for other tests to reach definitive diagnosis in your case.
Hope this helps. Take care.
Note: This post is not to emphasise final diagnosis as the same cannot be made online and is aimed just to provide medical information and no treatment suggested above be taken without face to face consultation with health care professional.