What is Plan B?

Even if you’re using protection, there’s always a chance that you could get pregnant. Perhaps you’ve turned to Plan B to avoid an unplanned pregnancy. But, what happens if Plan B fails? It’s crucial to understand your options so you can plan your next steps!

Today, we’re discussing Plan B — including how it works, the difference between Plan B and the abortion pill, and what to do if you still get pregnant after taking it. Keep reading to learn more!

How Does Plan B Work?

Plan B is a form of emergency contraception that lowers the risk of pregnancy by preventing or delaying ovulation. It’s often used when women accidentally forget to take their birth control, when their birth control fails (for example, condom slippage or breakage), or if they’ve experienced sexual assault[1]. It’s important to know that Plan B (and all other forms of emergency contraception) is only intended for backup use, not as a primary method of birth control[1].

Is Plan B an Abortion Pill? What’s the Difference?

While they seem similar, Plan B and the abortion pill are not the same things. The difference is that Plan B aims to keep you from getting pregnant in the first place, while the abortion pill ends a pregnancy that has already begun. 

If you have been sexually active in weeks prior to taking Plan B you may want to take a pregnancy test or even receive an ultrasound just to be certain that you’re not pregnant from a previous sexual encounter.

Can Plan B Cause Miscarriage?

While the goal of Plan B is to prevent pregnancy altogether, it can cause early miscarriage in rare cases[2]. This happens when the egg has already been fertilized but is prevented from implanting properly in the uterus. The embryo never has the chance to develop into a viable pregnancy and is eventually miscarried.  

How Effective is Plan B? When Can I Take Plan B? 

Plan B is most effective when taken as soon as possible after having unprotected sex. It will continue to reduce the risk of pregnancy for up to 120 hours (5 days)[1]

Does Plan B Have Side Effects?

Common side effects of Plan B include[1]:

  • Dizziness
  • Headache
  • Fatigue
  • Cramps or abdominal pain 
  • Nausea or vomiting
  • Breast tenderness
  • Delayed period (up to a week), heavier bleeding during your next period, or bleeding between periods

These side effects should be mild and only last a few days. However, if you experience bleeding or spotting for longer than a week or severe lower abdominal pain three to five weeks after taking Plan B, contact your healthcare provider immediately, as these symptoms can indicate a miscarriage or ectopic pregnancy has occurred[1].

What to Do if Plan B Fails

If your period is delayed for more than three to four weeks, it may be a sign that Plan B has failed[1]. The next step is to determine whether or not you’re pregnant. Consider scheduling a free pregnancy test and free ultrasound at Pathway Health Clinic! 

If your results come back positive, don’t panic. Our compassionate team is here to help you explore all of your pregnancy options so that you can make an informed and empowered decision! We will do everything we can to equip you to take your next steps with confidence!

Give us a call at (760) 945-4673 or request an appointment online today. All services are confidential and free of charge! 

Please be aware that Pathway Health Clinic does not provide or refer for abortion services. 


  1. Mayo Foundation for Medical Education and Research. (2022, June 3). Morning-after pill. Mayo Clinic. Retrieved from https://www.mayoclinic.org/tests-procedures/morning-after-pill/about/pac-20394730#  
  2. Embryocidal Potential of Modern Contraceptives. AAPLOG. (2020, January 15). Retrieved from https://aaplog.org/wp-content/uploads/2020/01/FINAL-CO-7-Embryocidal-Potential-of-Modern-Contraception-1.20.20.pdf