How do you know if Plan B worked?

The only way to know if Plan B has prevented pregnancy is to wait for your next period. If your period arrives more than a week late, you may want to consider taking a pregnancy test. Some women will experience light bleeding after taking Plan B and may take this as a sign that it’s worked to prevent pregnancy.

How long after taking Plan B do symptoms start?

Day 1: After taking the pill, you may experience mild side effects like nausea, vomiting, and pelvic pain. Some people may vomit within two hours of taking the pill. In this case, it is important to retake the pill to guarantee its effectiveness.

What happens if you take Plan B immediately?

The sooner you take Plan B®, the more effective it is. It can prevent pregnancy if taken within 72 hours and preferably within 12 hours of unprotected relationship. If you take it within 24 hours of unprotected relationship, it is 95% effective. If you take it between 48 and 72 hours of unprotected relationship, the efficacy rate is 61%.