Unless you had a second test, it's also highly likely that you had a false positive test, especially since the incidence of COVID in the population is still not that high
https://en.m.wikipedia.org/wiki/Bayes%27_theorem
Read the section on drug testing to see what I mean. The probability of false positives when doing mass testing of mostly healthy individuals is much higher than you would intuit, so it's very possible that you never had the pathogen at all