Yesterday i went into the er with left arm and shoulder pain. they did know test other than my vitals and said i had a pinched nerve can i trust that?

Pinched nerve: Sounds like the ER folks did a diagnosis of exclusion, i.e., ruled out some things and pinched nerve was left. To be sure, a neurologist needs to do a nerve conduction test called an EMG. After you know what is going on, consider massage and other natural and non-invasive treatments in addition to what your doc suggests. Peace and good health.