Thyroid disorders (hypo- and hyperthyroidism) can cause irregular menstrual cycles and periods. Birth control pills will regulate your periods but won’t regulate your thyroid gland. It is very important to find out if you are ovulating, or not. Women without ovulations usually experience irregular periods. Birth control pills will regulate the cycles but will stop ovulation. It is believed that after coming off birth control, ovulation can be established spontaneously and the menstrual cycles will increase in duration. This is the hope, at least.


Blood levels of thyroxin (T4) and thyroid stimulating hormone (TSH) should be checked to prove hypothyroidism. In primary hypothyroidism T4 is decreased and TSH is increased. In secondary hyperthyroidism that is due to pituitary gland failure both hormones T4 and TSH are decreased. You should ask expert help from an endocrinologist for examining your thyroid gland.