I don't smoke. I eat decently. I exercise. I don't have history of cancer in my family. But, I have a chest pain. It's severe, sometimes. It hurts right between my breast, especially when I breathe deeply (or it worsens when I do.) and when I press it, or put pressure there. Sometimes the pain actually moves to be more on my breast, or it will be right below, on my ribcage. Any ideas of what could be going on?