Skip To Content

    There's An Alarming Amount Of People Sharing Their "I Got Pregnant After Taking Plan B" Stories — Here's What You Need To Know

    Plan B is NOT the most effective form of oral emergency contraception.

    If you've been on TikTok recently, you may have come across quite a few people sharing their stories about how they got pregnant after taking Plan B (also known as the morning-after pill or emergency contraception (EC)).


    You can type "pregnant on plan b" in the TikTok search bar and tons of videos will come up, like this one and this one and this one.

    There's a scary number of videos, especially when the sole purpose of Plan B is to help prevent pregnancy! 😱


    So, we wanted to give you the best information possible — from an actual expert — about how the morning-after pill works, when it should be taken, and more*.

    20th Century Fox

    *PLEASE NOTE: This article is not to scare you away from taking emergency contraception — we still hope you DO take it if needed! We just want you to get the full information about how it works. Unfortunately, no birth control can be 100% effective, so all we can do is educate ourselves on which is best for our specific circumstances. 

    To learn everything we need to know, BuzzFeed spoke to labor and delivery nurse Vivian Nguyen, BSN, RN, WHNP-S.

    First off, let's discuss how oral ECs work. Basically, they prevent ovulation from occurring, so an egg can't drop from the ovaries and become fertilized by sperm.

    One kind is the levonorgestrel EC — which is what Plan B is. "Plan B is a single dose that contains 1.5 mg of levonorgestrel (LNG), a synthetic progestin hormone. It blocks the luteinizing hormone surge in the body that normally occurs before ovulation (the releasing of an egg from the ovary), thus inhibiting follicular development and egg release. If there is no egg released, there is no fertilization and pregnancy," she said.

    Several sets of contraceptive pills
    Peter Dazeley / Getty Images

    And there are many different types of EC options available that work exactly like Plan B, including AfteraAfterPillEContraMy WayNext Choice One DoseOpcicon OneStepOption 2, and Take Action

    Another type of emergency contraceptive pill, called Ella, uses a single dose of 30 mg of ulipristal acetate (UPA) to stop or delay the release of an egg from the ovary. "It should be taken within five days of unprotected intercourse (UPI) to prevent ovulation. It is the only emergency contraceptive pill that requires a prescription," explained Vivian.

    A woman being handed two pills
    Adam Gault / Getty Images/Science Photo Library RF

    And, although the copper IUD is a long-term form of birth control, it CAN be used as a form of emergency contraception if placed by a healthcare provider within five days of unprotected sex. "The copper IUD works by preventing fertilization by impairing sperm function. The copper causes an unfavorable environment in the uterus that inhibits sperm motility and reduces sperm survival," Vivian said.

    An inserted IUD
    Lalocracio / Getty Images/iStockphoto

    Once placed, the copper IUD remains a highly effective, semi-permanent form of birth control for several years. You can read more about how it may be used for emergency contraception here.

    Vivian confirmed that Ella is more effective than Plan B when it comes to preventing pregnancy and that the copper IUD is actually the MOST effective if it is placed.

    A woman standing in a pharmacy aisle comparing two boxes
    Alexanderford / Getty Images

    By the way, all ECs can be taken at any time during your menstrual cycle!!!

    Levonorgestrel emergency contraceptive pills are available over the counter to people of any age. "There is no ID, prescription, or age requirement for purchase. It can be found in the family planning or feminine hygiene aisles at your local drugstore like CVS, Walgreen's, Target, and Walmart," she said, adding, "Until August 2013, a prescription was required for women under age 17 to purchase Plan B, but this restriction has been removed."

    A person checking out at the pharmacy
    Getty Images

    (Almost everyone is a candidate for ECs — if you have concerns, talk to your healthcare provider to discuss your specific circumstances.)

    All emergency contraception should be administered within five days of unprotected intercourse, although they are MOST effective within three days. "If Plan B is taken within 24 hours of unprotected sex, it is 95% effective. If it is taken between 48 and 72 hours of unprotected sex, the efficacy rate is 61%. Therefore, it is best taken within 24 hours of unprotected intercourse."

    A person sitting in bed and taking a sip of water to go with their pills
    Asiandelight / Getty Images

    Unfortunately, the effectiveness of emergency contraception depends on multiple factors, including bodyweight. "The efficacy of emergency contraceptive pills may decrease with increased body weight for overweight (BMI > 25) and obese (BMI > 30) individuals," explained Vivian.

    A person standing on a scale
    Osakawayne Studios / Getty Images

    You can read this story about a Canadian woman's experience buying Plan B as a 165+ pound person.

    Bodyweight does not affect the efficacy of the copper IUD if it is used emergency contraception, however. Other things that can affect the efficacy are if the person had sex in their fertile window and how many unprotected intercourse exposures the person had in their cycle.

    Another downside to EC is that if ovulation has already occurred, it will not prevent pregnancy. However, a person or provider is not likely to actually know which day ovulation occurs, so it is not a bad idea to take the pill just in case!

    A calendar surrounded by EC pills, a watch, a pair of eyeglasses, and a tampon
    Carol Yepes / Getty Images

    "Ella is more forgiving because it delays ovulation in both the pre-ovulatory period and after the LH surge has started. This is why Ella is more effective than Plan B and other levonorgestrel emergency contraceptive pills," Vivian added.

    After you've taken an EC, how will you know if it has worked? Sadly, the only way to definitely know that it worked is to wait for your next period to arrive. If you do not start your period within the week you expect it, take a pregnancy test, and consult your healthcare provider.

    A person looking at a pregnancy test
    Zave Smith / Getty Images/Uppercut RF

    The side effects you may experience include bleeding, nausea, vomiting, and fatigue, but Vivian said that, overall, they should be minimal and tolerable.

    And that's what you need to know about emergency contraception in a nutshell. "My advice is to always have EC pills on hand because you never know when you may have an accident and will need it — especially since it's a time-sensitive medicine that works better the sooner it's taken."

    TL;DR: The people who took the morning-after pill in all of those TikToks could have gotten pregnant for a number of reasons, including the possibility that they had already ovulated, that they were already pregnant, and/or that the efficacy of the pill decreased due to body weight.

    Want awesome parenting tips in your inbox twice a week? Sign up for the BuzzFeed Parents newsletter!

    Newsletter signup form