How can I know if someone has tracked my Tail Number?
I doubt you can. Anyone can create a receiver and feed to a number of services. They can even run a receiver and not feed any services.
You want to check your own plane on flightaware?
You’ll need to be logged in and search for it.
Same procedure on other sites.
Individuals with their own receivers will have no problem tracking you, no matter if you are on a block list.
But the association between ModeS hex/ ICAO id and your tail number might not be straight forward if you are outside the US.
Or even in the US you could have the ICAO id set wrong. (which should not happen anymore with the ADSB-test which are required)
What transponder do you have in your aircraft?