Hi, I have gone through your query and understood the concern. You did not have to take the emergency contraceptive in the first instance, since you were in the safe period of your menstrual cycle when you had the intercourse. The pill contains high dose of hormone and this disturbs the hormone milieu. This can also delay the next natural period by a week or two. So, you need to see a specialist for further help if you become overdue by ten days. You will need tests to exclude pregnancy which has a rare chance, and hormones to induce a period. Please do not self-medicate without proper guidance. Hope this helps.