Has this ever happened to anyone??? I have been sleeping on my side due to being pregnant and I sleep on my side anyways, but a couple of days ago I woke up with pain in my left shoulder. It's pretty bad considering I notice it every time I move my arm or my neck. Sometimes the pain is so bad it sends shooting pains down my left arm. I rotated sleeping on my back and my side pre pregnancy, but now only sleep on my side and I'm wondering it this is causing stress to my shoulder???