Maybe a second consult w/ another Dr. would confirm and make you feel more at ease about it..
Know the feeling my hubby has had thyroid cancer for 17 yrs now ..
and though it is under control it is always at the back of my mind...
His blood work is not where Dr.s like to see it , 0 thyroid and it has always read around 12-21
and going up slowly which means there is still a little piece of tissue..
but just consulted w/ another dr and he reasured us that it is still under control..
good luck and hope you find some piece