How To Prevent Pregnancy After Unprotected Sex

Want to avoid an unplanned pregnancy? There are options if you've had unprotected sex.

Almost half of pregnancies in the United States are unplanned, with the highest rate between the ages of 18 to 24.

If you dread having to make the difficult, life-altering decisions that come with an unplanned pregnancy, there are options for emergency contraceptives that can be effective if you use them within days after unprotected sex (aka condomless sex).

Here's what you should know about those emergency contraception options, as well as some other considerations.

What To Do After Having Unprotected Sex

After having condomless sex (or having sex where the condom breaks), you'll want to first use the bathroom and clean up any fluids from your genital and anal regions to reduce your risk of developing a urinary tract infection (UTI)

Peeing also helps wash away those fluids. But note that this will not reduce your chance of pregnancy.

UTIs occur when bacteria enter and colonize inside the urethra. It can also spread to the bladder and kidneys. Some UTIs resolve themselves, but sometimes, you will need to take a course of antibiotics.

But one thing you shouldn't do after unprotected sex? Douching.

"Douching will not increase the risk of pregnancy, but it may increase the risk of pelvic infections," Lisa Perriera, MD, MPH, a board-certified OB-GYN based in Pennsylvania, told Health. "Douching, in general, is a bad idea."

That's because it alters the normal balance of yeast and bacteria in the reproductive tract, which could lead to an infection.

Get Tested for Sexually Transmitted Infections (STIs)

One of the best ways to prevent sexually transmitted infections (STIs) while engaging in vaginal, anal, or oral sex is to use condoms.

If you are sexually active, you should receive regular tests for STIs—including gonorrhea, chlamydia, syphilis, human immunodeficiency virus (HIV), and hepatitis B and C virus. 

It's a good idea to receive a test within a couple of weeks of unprotected sex. However, if your HIV and hepatitis test results are negative, you'll need to get retested in another six months to be absolutely sure. Some tests for those viruses take anywhere between a couple of weeks to six months to detect the viruses in your body.

If you think you've been exposed to HIV, you can take a course of post-exposure prophylaxis (PEP) within 72 hours of exposure. However, PEP is generally reserved for high-risk scenarios.

How Effective is Emergency Contraception?

Using emergency contraception doesn't guarantee that you will not become pregnant but it can certainly reduce your risk. According to one study published in 2019 in Cochrane Database, researchers reported that people who took the morning-after pill Plan B had a 1.1% to 2.4% chance of getting pregnant. However, according to the World Health Organization, it can reduce your risk of pregnancy by up to 95% or more.

However, that means you'll still need to keep an eye on your menstrual cycle after having unprotected sex, bearing in mind that a morning-after pill can cause spotting and may alter the flow of your period. That can make it hard to tell whether you are pregnant, so if your period is more than a week late, take a pregnancy test.

You can also become pregnant after having unprotected sex during menstrual bleeding, though it's less likely. Per the National Library of Medicine, sperm can live inside your reproductive tract for as long as five days. And ovulation, the time when you are most likely to become pregnant, typically occurs about 14 days before your next period.

Still, using emergency contraception can certainly lower your risk of becoming pregnant after having unprotected sex. Here's what you need to know about three options to consider—including Plan B (levonorgestrel), ella (ulipristal acetate), and ParaGuard.

Plan B

Also known as a morning-after pill, Plan B is one of the first hormonal products approved by the Food and Drug Administration for emergency contraception. 

A progestin-only pill, Plan B can prevent ovulation and fertilization if you take the pill within three days of having unprotected sex. However, the sooner you take it, the better, according to the CDC.

Anyone can buy Plan B and its generic counterparts over the counter, meaning you don't need a prescription (although you may have to ask the pharmacist). Plan B costs between $20 and $50.

You should keep it on hand for emergency cases, Christopher Estes, MD, a healthcare provider specializing in functional medicine at the Miami Beach Comprehensive Wellness Center in Florida, told Health.

Side effects of Plan B include:

  • Changes to your next menstrual cycle
  • Nausea or vomiting
  • Abdominal pain
  • Fatigue
  • Tender breasts
  • Dizziness or headaches

If you vomit within two hours of taking Plan B, you'll need to take another pill to ensure its effectiveness.


Like Plan B, ella (or ellaOne) is an emergency contraceptive approved by the Food and Drug Administration. Generally, it works the same way as Plan B, except it's effective if you take it as many as five days after having unprotected sex.

Additionally, while Plan B is progestin-only, ella is ulipristal acetate. According to one study published in 2011 in the journal Pharmacy and Therapeutics, ulipristal acetate works by attaching to receptors on progesterone molecules and creating an anti-progesterone effect inside the body. 

That effect suppresses ovulation and prevents the endometrium (the tissue that lines the inside of the uterus) from becoming thick. Ovulation and a thick endometrium are necessary for pregnancy to occur.  

The side effects of ella are similar to those of Plan B, and include nausea, tiredness, headache, and dizziness.


Another type of emergency contraception is ParaGuard, a hormone-free, copper intrauterine device (IUD). ParaGuard needs to be inserted by a healthcare provider within five days after having unprotected sex.

"It seems to work by increasing cervical mucus and repelling sperm," Beth Jordan, MD, a board-certified internist based in Baltimore, told Health.

Unlike the two emergency contraceptive pills, Paraguard is effective at preventing pregnancy for up to 12 years if it remains in the proper place.

It could be costly, however, if your insurance doesn't cover it. According to Planned Parenthood. ParaGuard costs anywhere between $500 and $1,000. 

Side effects include cramping and bleeding between periods. However, those side effects usually go away after the first few months.

A Quick Review

If you have unprotected sex, find a method of emergency contraception immediately. In addition, this is a good time to carefully consider your future birth control options. Make an appointment to speak to a healthcare provider so you can figure out which are the safest and most effective choices for you.

Emergency contraception can have side effects and may or may not prevent pregnancy. So while it is helpful if other methods fail you should not do not rely on this method for birth control.

Instead, invest in a more reliable form of birth control, like the birth control pill, patches, shots, vaginal rings, or IUDS, among others. And to prevent STIs, make sure you are correctly using condoms.

"Many condom failures are just due to improper use," said Dr. Estes. "It's not put on the right way, it's not worn the right way, you roll them inside out. When putting on a condom, you need to know exactly how to place it, from start to finish."

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  1. Centers for Disease Control and Prevention. Unintended pregnancy.

  2. MedlinePlus. Urinary tract infections - adults.

  3. Centers for Disease Control and Prevention. How you can prevent sexually transmitted diseases.

  4. Centers for Disease Control and Prevention. PEP (post-exposure prophylaxis).

  5. Office on Women's Health. Urinary tract infections.

  6. Haeger KO, Lamme J, Cleland K. State of emergency contraception in the U.S., 2018Contracept Reprod Med. 2018;3(1):20. doi:10.1186/s40834-018-0067-8

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