Hi Welcome to HEALTHCARE MAGIC..
I have gone through your query and can understand your concern...
Emergency pill like postinor 2 prevents pregnancy by inhibiting
implantation of fertilized egg on to uterus. It is 95% successful if taken within 24 hours of having sex. So chances of pregnancy are very less in her.
Most probably her period are delayed. Delayed period after intake of emergency pill as postinor is a common problem. It is known side effect due to high dose of hormone levogesterol contained in the pill.
One should never use emergency pill as regular method of
contraception. Use condoms or regular
contraceptive pills to prevent pregnancy in future. Frequent intake of emergency contraceptive pills can cause serious problems like
irregular periods, ectopic pregnancy, ovarian hyper-stimulation syndrome & even
infertility.
You should also do a pregnancy test to ruleout pregnancy possibility.
If your period doesn't occur even after 7-10 days, Consult a gynaecologist
Hope this information helps