Hello mam, thanks for trusting health care magic.
In my opinion do a urine pregnancy
test now only and see for result it can be early pregnancy.
If test is negative nothing to be done because it was probably due to the effect of emergency pill only and will resume her normal period pattern eventually.
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.