Hi & Welcome. Norethisterone is a Progesterone hormone which is mainly used to regularize abnormal menstrual bleeding, lack of monthly menstrual bleeding, delayed periods in certain conditions like polycystic disease of the ovaries, to prepone or postpone the period, etc. It is useful where the luteal phase defect (progesterone deficiency) causes infertility. In your case it is useful in regularizing menstrual cycle. It can be used 10 mg twice daily from 11th day to 25 th day of cycle. You can use it for 3-6 cycle. Since you wish to conceive, you should get yourself thoroughly evaluated by an infertility specialist for the cause of irregular periods which can be due to hormonal imbalance, diseases of the ovaries or uterus, certain underlying medical illness or hypothyroidism. You may be required to get the following workup done: Thorough internal check up - per vaginum and per speculum. Pelvic ultrasound scan done transvaginally. Hormonal levels - FSH, LH, TSH, Prolactin, OGTT, DHEAS, Free testosterone, lipid profile, etc This will reveal a diagnosis which can be treated effectively and thus enable you to conceive. Hope these answer your query.