Hello 3 Days Ago My Right Arm From My Elbow

Hello 3 days ago my right arm from my elbow to shoulder began to ache and yesterday there was a bruise the size of a dime and today the pain has mellowed a bit but the bruise is the size of an apple. And as of this morning my left arm in the same spot is hurting 3-4x more then the right arm did... i did not fall or injure myself this just happened randomly.. also today my left arm goes numb for 5-30 mins at a time. Sorry for long question but i dont have a family Doctor as mine retired in July. Thanks in advance!