at the first instance u should have tested ur blood for Anti TPO level. if ur TSH is between 3.5-10 then only if Anti TPO is positive we start euthyrox
tablet, if TSH was more than 10 then tablet is started any way. bit now since u r in ur 28 th week. just continue with ur medication. TSH level
in third trimester is 0.25-2.5. post partum stop ur medication and after 6 weeks check for ur TFT and anti TPO. if fine that's that otherwise u need treatment.