I had a pain that started under my right armpit and grabbed (like a muscle spasm)- the pain went from upper right chest, wrapped around armpit to shou?

Muscle spasm: You made a great diagnosis. Yes some muscle spasm can go from the front of the chest around to the back. Hint: No heavy exercise, use Advil or Aleve (naproxen) if not allergic and use 2-3 tennis balls in an athletic sock and place under the affected muscle. BioFreeze is an excellent liniment.

Possibilities: Would wonder about joint problem with shoulder such as a developing adhesive capsulitis, but also brachial plexitis (Parsonage-Turner), or referred nerve pain from neck or arm. We could expand upon your situation via a Concierge appt online, and be more thorough and provide more focused directions.