[Question] Myocarditis after Pfizer-BioNTech Vaccine

Israel Examines Heart Inflammation Cases After Pfizer Shot—Bloomberg

The day after I received my 2nd shot, I had an extremely uncomfortable feeling in my chest. My heart was beating rapidly and it was difficult to catch my breath after exertion. At some points I debated calling a physician or hospital. Has anyone else experienced similar effects? The article says the (potentially) linked cases happened primarily in men under 30, which happens to be my demographic. I am unsure if I had myocarditis of this kind, but it seems plausible.

My Fitbit thinks I spent 6.5 hours that day exercising (even though I spent almost the entire day sitting or in bed).