Hypothyroidism.
3 days off Medicine followed by
TSH and T3, T4 is normal,
It doesn't mean you do not require medicine.
Thyroid medicine is for lifelong, should not stop.
Only after one month of without medicine -if TSH is normal then only recommended to stop. the anti thyroid medicine.
You should continue same dose thyroxine 37.5 microgram before breakfast and
repeat TSH, freeT4 and free T3 after 1 month and review.