Suggest Treatment For Hyperthyroidism

hi Dr i am trying to conceive from past 3yrs after certain test i was dignesed with high thyroid and taking treatment for the same and they have given 100mg tablets as mine thyroid was 17% and later its reduced after 2 months to 0.011% and after 2 months of medicines its comes to 0.091% Now doctor has asked me to reduce to 75mg and my menses are regular. Please suggest