Hello, Letrozole induces ovulation during infertility in women. It helps stimulate ovulation by inhibiting estrogen production. However, it can cause menopausal like symptoms. If you are having irregular menses report to the doctor who has prescribed you the medicine. The Duphaston tablet does not delay periods or ovulation but can help correct menstrual irregularities in patients with progesterone deficiency. You should be aware that letrozole is also used to induce miscarriage in certain situations. Adding letrozole to misoprostol improves the success rate and decreases the interval between induction and expulsion in cases of first trimester miscarriage. Be careful of what medicines you are taking. Irregular periods after a miscarriage can be very common. Stay relaxed. Give yourself time to recover. Your body has been through hormonal changes, and it may take a few months before it gets back to normal. Take home made balance food rich in iron and protein. Stay away from anxiety and stress. Take care. Hope I have answered your question. Let me know if I can assist you further. Regards, Dr. Nupur K, General & Family Physician