Did your surgeon suggest stretching so soon?

Only a week out seems quite soon,
*do move the arm gently and lightly keep range of motion to keep fluids moving & tissues healthy, and so you don't get frozen shoulder.*

If Dr didn't approve or mention of stretches I would not do any til he OKs it..

Usually take it easy & slow for a couple of weeks is the general time frame post op.
Most have had a good amount of pain for a few weeks..

Avoid fast grabs/reaches or no rough car rides..

Take time and let it heal awhile...