Hi, Last Night I Noticed That In My Suprasternal Notch

Hi, last night I noticed that in my suprasternal notch I could see and palpate a steady heart beat. I have recently been diagnosed with pericarditis, however my current GP doesn't believe this to be the issue (which is what I believe too). I have recently had subacromial bursitis in my left shoulder (treated) and some form of injury to my left sc joint (nothing showed on the USS). Would it be from pressure being placed on the carotid artery, or could it be some issue related to pericarditis?