Can methimazole for overactive thyroid and metoprolol tartrate cause irregular menstrual cycles? i had regular cycles before i started taking these medications?

Medication: I am not allowed to make a medical diagnosis and provide treatment since this forum is solely for educational purposes. However, if you are taking those meds for hyperthyroidism, the disease itself is known to causes irregular periods. Or it could be due to other medical reasons unrelated to thyroid disorder. Best thing to do: see an obgyn doctor about irregular menses. I hope this helps.