I am feeling left shoulder and left arm mild pain. and when i walk i feel better. when i walk 10 to 20 days it will be alright?

Left shoulder pain: May be pleuradynia, inflammation of lung muscle vs. pleuritis/ pericarditis inflammation of the lung/heart surface- .It is viral inflammation - usually resolves on its own NSAIDS may help-get EKG . Rarely lesion in lung /chest so CXR would help in diagnosis. Very rarely could be clot for low risk could check d-dimer .Though no heartburn , may be reflux so can try ranitidine. f/u/ w/ MD