Ask them to check your thyroid antibodies (tpo antibodies) my thyroid tests were coming back (and still do) as normal because they only check tsh and mine is still in range but my thyroid antibodies were 646 and they're supposed to be around 11 or something like that.. so that's how we found out I have hashimotos!

Your blood tests shouldn’t alter heavily at all they may change a little during winter and summer. Sometimes you have to school your Dr. (I don’t know if they just look and see normal and ignore past tests). Also have them check antibodies (forget names there are 2) if you have any antibodies your body is under attack even if they have a “normal level”. Good luck

Are you seeing an Endocrinologist? They specialize in Thyroid disorders. Also have you had a Thyroid Scan?