I took meds for ADD for 13yrs b4 I stopped for pregnancy & nursing for3 yrs, was diagnosed fibromyalgia last year. If I use meds again will it affect?

Yes. Are you asking if the medication will be effective now? the answer is yes. If you are asking if ADD medications will affect fibromyalgia, then the answer is some medications may improve both. I would definitely talk with your doctor to find the right one for you.