Your period should come when you get to the placbo pills. These are inactive or with little or no hormones.
Bleeding is common and a minor side effect of using the Emergency Pill. Once you start you regular birth control pills, you will have to wait until you get to the inactive pills before your hormone levels are low enough to allow ovulation.
Hope this answers your question!
REFERENCE(S)
1. The morning-after pill, 2006.
Emergency Contraception - The Morning After Pill
2. BirthControl.com, 2006.
Birth Control,Birth Control Pill BirthControl.com