Dull left breast chest pain today. Comes off and on. Can pin-point where it is. What could this be more likely? Heart related? Thank you.

Multiple reason. It can be simple muscle pain or heart related,I will get the examination from your doc .
Dull chest. Pain. Not enough information to advise or possible etiology Need more information like any SOB or how long the pain last or any medical history . See your MD to rule out catastrophic causes of chest pain.