CDC says test won't be accurate for 5 days.
I've been following Covid news for over 2 years, been tested (other than when I was hospitalized) twice, and don't know what the

that is supposed to mean. Rapid antigen tests yield results in 10-20 minutes. They are a bit less accurate than PCR tests, but their accuracy does not vary with time. Similarly, PCR tests are not utterly perfect, but again, their accuracy does not vary with time.
The only guess I can come up with is that
MissMillie got one of
LIEden's "free" Covid tests some time ago, mailed her sample to ??, and the CDC says that ?? will communicate the results within 5 days. Of course, if
MissMillie received one of
LIEden's "free" Covid tests by mail, she'd better hope the USPS never allowed the test to get below the test's minimum temperature while it was in transit, and that the test didn't sit in
MissMillie's mailbox at too low a temperature for very long.