Not likely the heart
You are describing chest wall (usually musculoskeletal) pain, not cardiac discomfort.
Can also be caused by inflammation
of the lining of the lung (pleurisy
). Physical stress
or injury (over exercise
or "pulled muscle") or local viral or other underlying infections may be playing a role. If not responsive to rest, local heat, muscle relaxants
or mild analgesics, you need to talk to your doctor.