I am being 'watched' by my rheumatologist because I had an ANA test with a 1:1280 positive result. I had another test after that one, and it was back to normal. She stated that it was too high to be a false positive, and that while it could be caused by a viral infection, it may also be one of the first signs that I had something auto-immune happening. She did mention Lupus, but insisted that if I needed to worry, she would let me know. I also had to do a return urine test because the first test was 'off'... she didn't elaborate. The second was fine.
The reason I had the testing was joint pain, sun sensitivity, sensitivity to cold and relentless fatigue, which hit me like a truck. By the time I got into a rheumy and had the second set of tests, I was already feeling better. I had four weeks though, where I was scared of what was happening.
Since then, I have had muscle aches, an increase of pain, muscle weakness and other stuff that has lead her to the 'possible fibro' diagnosis.
I would say not to get all stressed, unless you notice several symptoms that seem to be more than fibro. I have had to make myself stop worrying about it, because my nerves couldn't take it. If the dr. is saying no, I would take him at his word, and move forward... at least until something that indicates more pops up. Worry, in itself, can make you sick. Good luck!!