Brief Answer:
lack of bleeding does not mean it did not work
Detailed Answer:
HI, thanks for using healthcare magic
Bleeding does not have to occur after the use of any form of emergency
contraception. Even if bleeding occurs, it does not signify if the pill worked or not.The lack of bleeding does not mean it did not work.
Nordette is effective if taken as you did, the first 4 pill within 120 hours and then pills after 12 hours.
Though emergency contraception is effective, it is not as effective as using regular contraception such as the pill. The oral
contraceptive pill , when taken accurately, has approximately 99% effectiveness rate at preventing unplanned
pregnancy.
It thought that is alot better to rely on this and other forms of protection (condoms, depo injection, patch, intrauterine devices) rather than the consistent use of emergency contraception. Emergency contraception , in general is considered to be 75% to 85% effective so regular contraception would be better.
I hope this helps, feel free to ask any other questions