Various pains, diag'ed w/fibromyalgia. Scared of heart issues due 2occasional pain along inner arm or front of shoulder. Dr/er visits/ekg/bloodwork ok?

Reassurance. If dr visits, labs, ekg have shown no specific abnormality, the pain is most likely muscular which would go along with the DX of fibromyalgia. The location if the pain can cause concern because everyone reads about those locations as the signal for a heart attack but in reality, muscles can hurt in that area without a cardiac cause. You were right to get it checked out.