Someone hit a blood vessel. ITS JUST A BRUISE! Your not going to die. It will dissapate after a week. Don't overstress the arm. If you lived in a town larger than 20 people, you would have seen a real doctor. We send the diaper heads out west. They can also be used to clean up oil spills.
Live in a town of 300,000, but whatever. I got better, faster medical advice on a boating forum than from the doctor. Horray for medicare. Praise Tommy Douglas.