This is anecdotal, and I still plan to get the latest booster soon, but I have had pain in my left chest since the first covid vaccine. I went to a doctor who ran an EKG but they said everything was functioning correctly. Maybe someone knows if I should get a second opinion? I can no longer sleep on my left side since then as it causes the pain to increase, so I don't believe it is related to myocarditis.
It's important to remember that you are n=1 and the timing could be a coincidence. It could be the vaccine. It could be stress from the pandemic causing angina. It could be lifestyle (do you exercise every day, eat healthily, sleep well, manage stress? - if not then angina in your 30s/40s is common).
It could even, as happened to a friend of mine, be a nerve issue in your chest muscles that's completely unrelated to your heart (aside: my friend was extremely relieved by this diagnosis which took quite a while to come by).