About a month ago, I came down with an upper respiratory illness that felt like a severe flu. Covid nasal swab test was taken 24 hours after first symptoms appe

About a month ago, I came down with an upper respiratory illness that felt like a severe flu. Covid nasal swab test was taken 24 hours after first symptoms appeared, and came back negative. Therefore I assumed it was flu. However given the supposedly very low base rate of flu during the current season, is it more likely from a Bayesian perspective that the Covid test was a false negative?