From 2021, modeling estimated 6% if you follow the 2 negative tests after day 6 or 10 day isolation rule; estimated 4% if you follow the 2 negative tests after day 6 or 14 day isolation rule.

From 2022, modeling estimated 2-3% if you have 2 negative tests testing daily.

I mean, you don't? You can look it up but recent advice was something like 10 days after first symptoms is when contagiousness reduces.

Anecdotally, my husband was sick on Friday and took rapid tests on Friday and Saturday (when he was very sick) and got negative. Then on Monday his rapid test was positive (followed by a positive PCR on Tuesday). So he was no doubt contagious on two days when he gave negative tests.