Hi, I also had that last year sometime. My Doctor said it was Costochondritis. I really was scared because it was right in the middle of my chest. It took about 6 weeks to go away. He said to take anti-inflammatories, which I cannot take due to stomach problems.

Heat helped me the most. But I then got the horrid rib pain on my right side under my arm down about 3-6 inches. It finally has went away with my recent pec minor surgery. Good Luck, Ihtos