Suggest Remedy For Absence Of Menstrual Cycle

hello my wife is a known case of hypothyroidism,started taking tablets one month ago, namely thyronorm 50 mcg.dr told to take it for three months then to check thyroid function test.since she started to take this she didnt have any episode of menstrual cycle.earlier she had been taking oral contraceptive pills for PCOD(cyctic ovarian disease)after completing this course the cyst size has come down and remains in follicles.i would like to know the reason for absence of menstrual cycle. will this affect our marital life. and also give the solution for this?