Pain

Yesterday, when I was running, I had a new pain hit me. I'm not sure what it was. I was starting on my second mile, and from the left side of my neck to almost my left eblow starting hurting. It was just a sharp pain, and, as long as I held my arm up, it didn't hurt. I finished the second mile, and went inside the gym. All of my vitals were good, so I'm not sure what it was. It was weird though.