I had a really bad cold-like illness in late November 2019, which left behind a severe sore throat which lasted about three weeks. It was notable because it wouldn't go away, to the point where I went to both urgent care and my primary doctor on separate occasions (I'm not one to go to the doctor unless I really need to.) Both times they took a look at my throat, proclaimed it to be a viral infection, and sent me on my way.

I too have wondered if I actually had Covid, but nobody knew how to diagnose it at that time.