Everyone is saying no, and I’m no expert, and I believe that for purposes beyond amusement value, the answer basically is no, but…

1. The times that I’ve had covid, the strength of the T signal has started weak, gotten strong, and then trailed slowly off over the course of days.

2. Same for family members.

3. Same for acquaintances who I’ve seen post day-by-day test photos on social media.

4. I’ve read that if you are vaccinated and boosted, your antigen response kicks in faster and so more closely parallels your communicability curve. That is to say that unvaccinated people will be communicable before home antigen tests start noticing that you’re responding. But people who have had covid or vaccinations will test positive sooner. And specifically I’ve read that during the incubation stage when you are infected but not very communicable yet the tests may miss you, but on the other hand that’s okayish because you’re not very communicable yet.

5. Everything that everyone has said about all the variability can be at least partially controlled, if you are using the same test batch, in the same location, at the same time of day, following the same idiosyncratic procedure for each.