Can right cervical nerve root compression cause symptoms on the left side, such as left shoulder/arm pain? i have severe foraminal stenosis.in c6/7.

Yes: Yes it can, although in this location the numbness and tingling usually goes to the hand.

Yes,happens alot: MRI & imaging attempt to give the best information in 2 dimensions as relates to the 3 dimensions of your body.It can be difficult for MRI readings to capture a correlation w/all of the symptoms you are experiencing.Presuming that you don't have a primary shoulder issue,the left sided symptoms are probably caused by the stenosis.Epidural injections can act as a diagnostic tool.Talk to your MD also