If there’s one thing we’ve all learned from the school of life, it’s to always be prepared. But the fact of the matter is that sometimes things just go wrong. This certainly applies to birth control—and it might explain why around one in nine sexually active women in the U.S. have used emergency contraception.

Also known as “the morning-after pill,” “day-after pills,” “post-coital contraception,” and “emergency contraceptive pills (ECPs),” emergency contraception (EC) works in much the same way as regular birth control pills, only it contains a higher dose of hormones. These hormones prevent the ovaries from releasing eggs and also block sperm from reaching and fertilizing an egg. There are currently three FDA-approved ECPs: Plan B One-step, Next Choice One Dose, and Ella. Only Plan B and Next Choice are sold over the counter.

Despite its obvious benefit, there’s plenty of buzz surrounding the morning-after pill that would make anyone think twice about taking it.

In the 40 or so years that it’s been around, EC has faced its share of controversy, particularly from pro-life organizations as access has expanded to younger women and certain kinds of ECPs no longer require a prescription. Despite its obvious benefit (i.e., enabling women and their partners to choose when and whether they are ready to parent), there’s plenty of buzz surrounding the morning-after pill that would make anyone think twice about taking it: Will taking EC make users infertile? Does it come with terrible side effects? Here, we discern fact from fiction.

10 Myths About Emergency Contraception

1. Myth: Emergency contraception can cause abortion.

Fact: Emergency birth control does not cause an abortion. While it’s been shown to be anywhere from 52 to 94 percent effective (when used correctly!) at preventing an unwanted pregnancy, if a woman who is already pregnant takes EC, it won’t end the pregnancy. The morning-after pill just isn’t effective if a fertilized egg has already attached to the uterine wallEmergency contraception: a review of current oral options. Mendez, Marisa. West Journal of Medicine, May 2002; 176(3):188-191.

Worry not: Taking EC won’t send anyone’s body into a tailspin—or put them at medical risk.

2. Myth: Emergency contraception has horrifying side effects.

Fact: Worry not: Taking EC won’t send anyone’s body into a tailspin—or put them at medical risk. Although emergency birth control pills have a higher dose of hormones than regular birth control pills, they generally don’t differ much when it comes to side effects. Taking the morning-after pill could result in side effects like nausea, headache, dizziness, breast tenderness, tiredness, and period changes—all of which are also common with regular birth control pills. (That said, it’s always a good idea to consult a medical professional if you’re experiencing severe side effects.).

3. Myth: Emergency contraception prevents pregnancy for a long time.

Fact: The morning-after pill doesn’t give anyone a free pass to have unprotected sex after taking it. Having unprotected sex in the days or weeks after taking the pill can still result in pregnancy, so it’s best to hold off on sexytimes until securing a reliable method of contraception.

Emergency contraception use won’t affect future family planning.

4. Myth: Emergency contraception might affect a woman’s chances of having a baby in the future.

Fact: Just like regular birth control, emergency contraception use won’t affect a woman’s future ability to get pregnant, neither will emergency birth control.

5. Myth: Alcohol or drugs in the bloodstream mean you can’t take emergency contraception.

Fact: Don’t let a night of partying stop you from taking the morning-after pill. Having alcohol, tobacco, or other drugs in your system when you take EC won’t change its effectiveness.

6. Myth: Emergency contraception can be taken any time after having unprotected sex and still be effective.

Fact: While no one has to take EC the second the sun rises after having had unprotected sex (making “the morning after pill” a bit of a misnomer), the sooner the better—EC’s effectiveness depends largely on how quickly it’s taken. Both Plan B One-Step and Next Choice One Dose should be taken as soon as possible—and no more than 72 hours after having unprotected sex. Ella remains effective for up to five days after unprotected sex, but it’s still smart to take it ASAP.

7. Myth: It’s okay to use emergency contraception instead of regular birth control.

Fact: There are a few reasons people shouldn’t rely on EC as their sole protection against pregnancy. First and most importantly, EC simply is not as effective as regular birth control. Second, emergency birth control pills are way pricier at up to $65 per single dose—not the most economical option.

The number on the scale might play a part in how well emergency contraception works.

8. Myth: As long as it’s taken early, the pill has the same effect on everyone.

Fact: Women with a BMI higher than 25 might not reap the same benefits as users with lower BMIs: Research shows that obese women are three times more likely to become pregnant than those with a lower BMICan we identify women at risk of pregnancy despite using emergency contraception? Data from randomized trials of ulipristal acetate and levonorgestrel. Glasier, A., Cameron, ST., Blithe, D., et al. Contraception, 2011 Oct;84(4):363-7. Overweight women are better off taking Ella, but even that appears to be less effective in women with a BMI higher than 35.

9. Myth: Emergency contraception is hard to get.

Fact: Emergency contraception—Plan B in particular—is now easier to get than ever. In 2013, the FDA gave its approval to make Plan B One-Step available over-the-counter (OTC) to women who are at least 15 years old. Thanks to another recent FDA decision, generic versions of the morning-after pill will now be available OTC without any age restrictions—although the labels will say that they’re intended for women who are 17 and older (which is somewhat puzzling, since no one is required to show proof of age).

10. Myth: Emergency contraception will harm a developing baby.

Fact: The verdict is still out. While EC doesn’t seem to cause birth defects, it’s worth noting that there haven’t been any reliable studies that looked at women who had a baby after taking the morning-after pill. That said, science has looked into whether or not regular birth control pills (which contain the same hormones as EC brands Plan B and Next Choice, but at a lower level) have affected children whose mothers continued taking the pill before realizing they were pregnant. The results: There was no increased risk of birth defects in these children. The effects of Ella on a developing child are unknown.

The Takeaway

One more fact we know for sure: Taking emergency birth control (or birth control in general) is a personal decision. On the flip side, so is having a baby—especially if it’s one you weren’t planning for. While these decisions may not be easy to make, being armed with knowledge could help steer you in the right direction—whatever that may be. ­­