My understanding is that those who have recuperated from the virus must test negative twice before being allowed to end their quarantines. I've also read that one can shed live viral cells for about 6 weeks after recovering. And then again, some people test negative even when they have the virus, as the tests aren't perfect plus the test can be done incorrectly.
It's quite confusing, isn't it?
I think the truth is that we don't know enough yet about this virus. I read traditional news reports as well as medical reports, sometimes for hours a day, and I've come to the conclusion that we still have a lot to learn about COVID-19