I suspect it was simply a false positive test. If you get covid, your body begins to produce antibodies. Especially if you're handling covid well. It takes at least a week for those antibodies to drop off after you've fought off the virus. You'll continue to test positive during that time. Last December, my accountant called to tell us that he'd tested positive for covid. We got tested and found we were positive too. We had no symptoms because we were both vaxed and boosted. Still, we self quarantined for a little over a week until we were testing negative for a couple of days. This experience made think back on the Trump episode.