Hi,
You might want to check out the info from this website:
nahypothyroidism.org/thyroid-hormone-transport/. It explains how you can have normal lab tests and still be hypothyroid. The doctors on this site recommend "A combination of the serum levels of TSH, free T3, free T4, reverse T3, anti-TPO antibody, antithyroglobulin antibody and SHBG should be used in combination of with clinical assessment and measurement of reflex speed and basal metabolic rate to most accurately determine the overall thyroid status in a patient."
HTH.
Kathy