I have myasthenia gravis&curious about pain and weakness. I'm doing ivig 's taking my meds, my muscles get sore & "feel" weak. Is this my mg acting up?

Maybe low grade. Symptoms fluctuate do to the nature of a neuromuscular synaptic process, and exertion can exceed control on occasion. Do not get discouraged, as weakness and fatiguability is part of the landscape here. Glad you doctor is using mixture of meds. A few months of ivig should provide added stability.