Can Thyroid Cause Irregular Periods In Female Patients ?

My wife is suffereing from thyroid since 2007. Reported TSH 7.95. After that through consultation now it is 3.15. ( T3=110 ng/dl, T4=9.7ug/dl). Taking daily THYROX-50 one tablet in the morning. But since the time of reporting of thyroid she is having regular problem in periods. It is very irregular in nature. Initially as per prescription we used DEVIRY for 10 days and after that regularly DEANXIT. While taking regular DEANXIT it was reported timely period but as soon as we stopped taking the same the problem started again. Now it is more than two months no period is coming. Pregnency test is -Ve. Can i get proper guidance for recovering the problem. She is 32years old and we have two baby girl. She is having migrain as well.