Doctors can you tell me how often should you get your thyroid checked?

Depends on condition: It depends on what is going on. If you are on a stable dose of levothyroxine and feel well, yearly is fine. If you are adjusting your dose, then you should wait 6 weeks to see the effects of a new dose. If you are being treated for hyperthyroidism with methimazole, the interval depends on symptoms, drug dose, rx goals and many factors, but probably every 6 weeks or so initially, then less.