Have upper shoulder blade pain mild comes and goes last few months2 x rays show nothing. What could this be? Scared of a pulimary embolism. (anxiety)

Subscapular bursitis. We all have a bursa (soft tissue lined space with thin film of fluid) at most of our bony prominences where there is expected movement between juxtaposed structures. Such is the case between your shoulder blade (scapula) and ribcage/muscles. This bursa can become inflamed (bursitis) and generate more fluid which can trigger a local pain response. Rest, NSAIDS, and a scapulothoracic rehab may help.