My Left Arm Is Tender To Touch Especially At Outer

My left arm is tender to touch especially at outer shoulder area. It feels weak from back top of arm to hand. Just hurts and feels weak. This has been going on for 2 to 3 days. My range of motion is impaired-can't lift upright without pain. If it's worth mentioning, our new puppy scratched my nose with her teeth and although it's not deep, it did bleed. That happened 3 days ago.