Left shoulder/back pain? muscular or something else?

I'm almost 3 weeks post RNY (7/18) and am having back pain/spasm feels like muscular?  I don't know if it's just because I pushed myself too hard Thurs eve on a walk when I met up with a friend and thought I'd keep up with her (big mistake, spent yesterday nursing a hamstring all day long!). Today and a couple of other times, I've had a pulling type pain at the base of my Trapezoids, today it is really focused on the left.  About a week after surgery this happened after the first night I was able to sleep on my side instead of my back.
Really hurts when I deep breathe -except when I am sitting upright in a chair with perfect posture. . .
Should I call the doctor, take one of the muscle relaxers/antispasmotic my surgeon prescribed for after surgery?
Thanks for any thoughts/ideas or similar stories. . .

I don't know if it has been too long but when I had surgery or any surgery for that matter the gas they use always goes up into my shoulders and my back and it feels like a muscular thing. But you being almost three weeks out you would think that all that would be gone by now. Hmm...maybe with you being on pain killers you pulled something and didnt know it till now???  If your worried though you might want to call your doctor if anything just for some peace of mind. I hope you get to feeling better!

I was given pain killers & the muscle relaxers to use after surgery but I only used them each one time, the day I came home from the hospital 7/20.  I'm thinking I'll tough it out through tonight & give a call in the morning.  Thank you!!!

It's probably trapped gas.  If you have pain meds, use them!  Nobody gets medals for
"toughing it out".

Good luck!

I am almost years out and I remember having pain at my left upper back.  It gradually resolved about 1-2 months later.