What Causes Pain In Arm Pit Radiating To Elbow?

Hello, yesterday I noticed under my armpit what it felt like a swollen gland but when I went to touch it there is nothing there but soreness. Then the pain that is going from the arm pit to my elbow and the vain is bruised, and raised. Also, my arm looks a little swollen and I am a little scared. I had surgery like 3 years ago on my breast area close to the armpit to remove an unknown mass that my body developed after taking birth controls. It wasn t cancerous. Could this be related Or could this be something different. Why the vain feels hard, I didn t do any heavy lifting at all.What do you Recomend ?