I was stabbed in my upper left side just below my arm pit, the cut was so deep it was only a quarter inch away from my heart. About 2 days after I was sitting down and all of the sudden I got an intense, sharp pain in my heart/shoulder blade, basically my whole upper left side (not including arm), it was difficult to breathe. The pain was very, very intense at first then throughout the next 10 minutes or so the pain came and went. The doctor said I didn't hit any vital organs so Im wondering what it could be.