Generally the difficulty I have in questions like this is that often the answer is couched in Boolean terms which are useless to me.

It's not like its "At 24 hours you were not contagious at all and couldn't spread it to anybody, then at 25 hours all of a sudden you were 100% contagious and will spread it to everyone you ever talk to, then 5 days later you will be 0% contagious again and cannot spread it at all." It begs the question, how contagious do you have to be before a virologist will call you "contagious"? What's the actual cutoff they're using? It's not Boolean so what is it? The answers are often couched in terms as if it was, which frustrates me as a layman.

As someone who was vaxxed but got Covid-19 a couple of weeks ago, I still have a slightly drippy nose making me have to clear my throat of mucous about once an hour or so. All other symptoms but that one only lasted a few days and I feel absolutely fine. I can't tell when it's going to start being okay to visit other people again. The isolation and cancelled plans are frustrating me, and home antigen tests are still positive even though I feel just fine. How contagious am I really? It's probably not completely impossible for me to spread it, but it's probably nowhere near as likely as it was back when I was 4 days into it and was having high fever, headache, and constant snot everywhere.