When women take Plan B as directed, about 7 out of every 8 women who could have gotten pregnant will not become pregnant after taking Plan B.
What are the chances of Plan B not working?
One-dose emergency contraception pills prevent pregnancy about 50-100% of the time. Some reasons emergency contraceptive pills can fail include ovulation timing, BMI and drug interactions.
What do you do if Plan B doesn't work?
Next steps after emergency contraception
- Continue to use birth control and protection. Once you've used emergency contraception, continue to use your regular birth control methods when having sex, to prevent pregnancy. ...
- Take a pregnancy test. ...
- Get screened for STIs.
