Home test kits ("rapid antigen") have higher false positive and higher false negative rates than the test that labs and hospitals use, which detect genetic material specific to the SARS-CoV-2 virus (PCR test). Rapid antigen tests are less precise, and users sometimes are sloppy (e.g. don't follow directions or accidentally contaminate test materials - test developers try to make the test kits idiot-tolerant, but nothing is idiot-proof).
If DU-member MustLoveBeagles was actually concerned, (s)he should have arranged - and now maybe should - to have a PCR test done at a local Walgreens or CVS or indie pharmacy. Or maybe just stay home for a week unless symptoms become serious and ask friends to deliver food and necessities if necessary (DU-member MustLoveBeagles should have bought an oximeter 3 or 4 years ago). If one compares Worldometers' Covid cases and deaths data for the US it can be seen that Covid became less deadly in mid-late 2021, and there have been fewer cases (compared to 2021) starting with 2022.
Anyone who thought Covid would magically go away in a year or so was fooling themselves. Covid has become like flu, seasonal background noise for most, serious or deadly for a few. It probably should be handled like a flu or cold, i.e. don't go to a hospital or ER unless symptoms become serious and be selfish rather than sharing it.