Hi Welcome to HEALTHCARE MAGIC..
I have gone through your query and can understand your concern...
Yes taking I-pill or an
emergency contraceptive pill could cause
irregular periods. Most probably your period is delayed. It is a common side effect of Ipill intake. It is due to side effect of high dose of levonorgestrol hormone contained in I pill. your period could be delayed for 1 or more cycles.
This pill works by preventing
implantation of fertilized egg on the wall of uterus. It is 95% successful if taken within 24 hours of having sex.
As you have taken the emergency contraceptive pill within 12 hours of intercourse, you should now relax. The possibility of pregnancy is very less in you.
Use condom or regular contraceptive pill as method of
contraception in future. Regular taking emergency contraceptive pills can cause problems like irregular periods, ovarian hyper-stimulation syndrome & even
infertility.
If your next period gets delayed by 2-3 weeks you should also do a pregnancy test to rule-out pregnancy possibility.
For more queries consult a gynaecologist
Hope this information helps