I don't know for certain. It's something I caught in late February/early-March, it caused what very clearly seems to be viral myocarditis, and by the time we all figured out that Covid-19 attacked hearts and other organs, it was long past the time I'd likely test positive, and also I was too sick to go out anywhere.

However, given the timing, Covid-19 seems like a good guess. I doubt very highly anyone else will have similar symptoms, though, as what I went through would have immediately killed most people. I have a weird genetic thing where I don't clot right, so I was okay, if very unsettled and uncomfortable!