When Will I Get Regular Periods After Taking An I-pill?

Hi, may I answer your health queries right now ? Please type your query here...i do the sex on 16th jan and take the i-pill after 2 hours of sex after that i was normal at all but today suddenly my periods are start however i recentaly complete my last period was came on 9th jan and finish on 14th jan so now this can be harmful or what about my next period pls guide me