The middle/ upper part of my chest has pains when I lay down or yawn in particular. Its more of a quick burst of discomfort. ..Should I be concerned?

Chest pain. Pain on inspiration or positiona changes (pleuritic pain) implies an inflamed area affected by that motion. Typically when symptoms are worse on lying down, it could imply pericarditis, although pleuritic pain could also secondary to inflammation in the pleura around the lungs.