###Human: Can I start Unwanted 21 after my periods? ###Assistant: Hello. Oral contraceptive pills are normally taken cyclically from day-5 of menses to day-24. I suggest taking tablet Norethisterone 10 mg twice daily similarly in every cycle. Oral contraceptives are ideally started from the start of a cycle, but if you want to start, start now from today and then stick to it regularly. Take the 21 tablets and then the placebos or choose the pill-free period for withdrawal bleed. The body takes some time to get used to it. Side effects could be headache, breast tenderness, high BP, clot formation, on long-term use irregular bleeding, carcinoma of the breast and endometrial hyperplasia that can lead to endometrial cancer. Hormonal contraceptives are better not used for many years. Better to change the method to prevent long-term side effects like after taking it for a year, you can have injection Medroxyprogesterone (three monthly) for few months, etc. For more information consult an obstetrician and gynaecologist online -->