How do i know if my immune system is working at top level ? covid (p) now ( n) after 21 days. thanks?

It's good to year your COVID has cleared. It is an urban myth (or old wives' tale) that people have "weak" immune systems that make them more susceptible to everyday infections (like colds) or make such infections worse. Stress, anxiety, poor sleep, and similar things may have such effects, but if you are generally healthy and feel well, then almost certainly your immune system is entirely normal.

Clinically if fine then 21 days too early to ck immune system . Give at least 6-8 weeks and can get IgG and IgM ckd clinical feeling is more imp

If you're covid positive and not having any symptoms, your immune system is working.