I recall reading some info from a doctor at the Cleveland Clinic that suggested waiting for 2 months after the surgery. So I think that would be the longest time to wait. If it had been a TT then I expect that testing sooner would be advisable; however, with the partial thyroidectomy I don't know how long it will take for the remaining thyroid tissue to respond to TSH stimulation and whether it can totally compensate for the overall reduced capacity to produce thyroid hormone. Another factor is that in the case of inadequate output from the remaining thyroid tissue, after starting on replacement thyroid medication it takes 4 weeks for T4 med to reach over 90% of its final effect on serum levels. So in view of all this, if it were me I would ask the doctor when he plans to re-test your Free T4 and Free T3 levels (not Total T4 and Total T3 levels). If more than 3-4 weeks, in view of the above, I would question why?
I would also ask for a copy of the blood test results from the time after surgery, and see what tests were done. If you get that info,and want our input, please post results and reference ranges.
Has the doctor given you any indication of what may have caused the hemorrhage?