Suggest Treatment For Shoulder Pain

I was a competitive gymnast for many years. Within a year of stopping the sport, i started to feel what felt like a knot behind my left shoulder blade...the spot would feel numb and radiate a pain down my arm. After a while, the pain decreased, but now, 9 years later, i have two children and am carrying them around a great deal. I have the pain back again, very strong. At night I feel like my arm is heavy, numb, tingling, painful, radiating. The pain goes from behind my shoulder blade, up to my neck and down my arm...even as i type my fingers feel strange and there is a strong sensation in my inner elbow and front of my shoulder. Is this likely a spine issue? or could it actually be a knot? I figure it is an injury from gymnastics, and just getting worse because of carrying the kids... should i contact a chiropractor? my pcp for an mri?