Hello mam, thanks for trusting health care magic.
In my opinion it is just the result of morning after pill which is a progesterone
and can adversely affect menstrual cycle.
You should wait for another 5 days and in case you still dont get your periods visit a gynecologist for prescription of withdrawl drugs.
In case you have further questions you can consult me on health care magic forum and i will be happy to help
Take care and wish you all the best.
Dr Manisha Jain.