Apparently, I had the flu in March

I had a flu shot in the fall, but I was also exhausted from grad school by spring. I was sick for almost two weeks at the end of March so I was hoping I had COVID-19 early, built some antibodies while my family did the same, and could feel somewhat protected in the classroom this fall (hopefully in a classroom of my own, but possibly substitute teaching). No such luck. Maybe I can plan better and go to the grocery store even less.