i-pill within the 24hrs, my periods still hasnt started?

Hi,
Welcome to ehealthforum,
Emergency contraceptive pills are effective in preventing pregnancy of taken within 24-48 hours of the intercourse. They remain effective for the next 12-15 hours. If your next unprotected intercourse was outside this time frame, then you would be at risk for pregnancy. Since the ECP contains high doses of hormones, they can disrupt the normal hormonal and period pattern causing delay in your next periods. Wait and watch for your periods/withdrawal bleeding. If pregnancy is suspected, look out for development of any other new symptoms suggestive of early pregnancy. Visit your doctor/gynecologist for further evaluation and assistance.
If pregnancy gets ruled out, and if you intend to remain sexually active, consider visiting your gynecologist to get started on suitable regular birth control measures to be protected (after your periods). Be regular with birth control use as instructed. Avoid having unprotected sexual contact.
Take care.