Suggest Treatment For Intermittent Pain Above Left Breast

I have been experiencing some intermittent pain in a weird location. It is a diagonal pain, above left breast, and heads toward left shoulder. Pain extends about 6 inches. I ve had some chiropractic because I thought it might be related to my cervical spine, and it goes away for a short period of time but then always returns. I had an adjustment today, and the pain was gone for about 5 hours, but it is back again now. It is not sharp, or constant, but feels kind of like a muscle pulling. If I turn my head tot the right, it definitely exacerbates the feeling. I haven t had any injuries. I m 53, good blood pressure, pulse, no diseases other than degenerative disc disease which is causing me lots of pain in my lower back and SI joint areas.