Can You Get Pregnant While on Birth Control?

The question alone may seem like a paradox, but since there’s no such thing as a miracle pill (or a miracle ring, or a miracle copper fork), you may not be surprised to learn that the answer to can you get pregnant while on birth control, is yes.

Current research shows that modern birth control options—including popular oral contraceptives—are more than 99.9% effective, but this is only true when they’re used perfectly. Also, that fraction of a decimal still means that pregnancy can happen.

If you’re wondering how it’s possible to conceive on birth control, it can be helpful to know which scenarios may lead to a breakthrough pregnancy. Below, we’ll review 5 occasions when you can conceive on hormonal birth control, and your timeline for restoring fertility when you’re ready to embark on the path to parenthood.

How effective is birth control?

Most statistics regarding birth control’s effectiveness describe their efficacy with perfect use . “Perfect use” means taking your hormonal dose at the same time every day, removing and reinserting your vaginal ring on schedule, or ensuring your IUD stays put.

Because alarms get snoozed, life happens, and human beings are imperfect, there are occasions when birth control can leave room for a pregnancy to occur. To that end, these are the use failure rates for non-barrier birth control options:

• LNg IUDs – .1-.4%
• Copper IUDs – .8%
• Hormonal implant – .1%
• Hormonal injection – 4%
• Oral contraceptives – 7%
• Hormonal patch – 7%
• Vaginal ring – 7%

Let’s explore 5 different scenarios that can result in birth control failure.

5 Times You Can Get Pregnant While On Birth Control

For the most part, hormonal birth control can be a remarkably dependable way to prevent unwanted pregnancy, in addition to mitigating other hormonally-related health concerns, like dysmenorrhea or endometriosis.

That said, there are certain usage errors and common scenarios that may result in a surprise pregnancy.

#1 You Missed a Pill Dose (Or More)

The most common explanation for getting pregnant while on birth control is straying off schedule when it comes to taking your oral contraceptive pill.

Oral contraceptive pills (OCPs or “the pill”) are the most popular method of hormonal birth control for American women, and with complete compliance, fewer than 1 in every 100 women will get pregnant.

However, if you miss a day of your pill regimen, your likelihood of conceiving may hinge on which type of OCP you’re taking:

• Progestin birth control – Progestin only pills, or “mini-pills,” use only one type of hormone to prevent pregnancy: progestin. While progestin only pills can completely halt ovulation for some women, around 4 in 10 mini-pill users will continue to ovulate while on their medication. To remain 99% effective at preventing pregnancy, the mini-pill must be taken within the same 3-hour window each day. With progestin-only pills, it is important to use backup contraception – like a condom – if an unintentional slip-up happens.
• Combination birth control – Combination birth control pills use two types of hormones to stop ovulation: estrogen and progestin. The addition of estrogen (the hormone that regulates the menstrual cycle) allows combination birth control to halt ovulation entirely. While you’re encouraged to take combination pills at the same time each day for consistency’s sake, veering a bit off track won’t necessarily impede your birth control’s efficacy. To understand more about ovulation while on birth control, read our detailed exploration in Can You Ovulate While on Birth Control. This is why most women are still highly unlikely to conceive if they miss one combined pill and make up for it by taking two on the following day.

The takeaway? Ovulation on birth control is not out of the question completely. Missing an active pill on either OCP regimen can augment your likelihood of getting pregnant, but your chances of conceiving with a progestin-only pill slip-up are much higher.

#2 You’ve Gotten Sick

If you’re taking an OCP and dealing with a bout of illness, your body may be more susceptible to getting pregnant.

There are two main symptoms associated with illness that can increase your likelihood of getting pregnant while on birth control:

• Vomiting – Before a birth control pill can kick into gear, it has to clear your digestive system and be metabolized. If you throw up, your stomach won’t have time to break down the pill and disburse the hormones needed to prevent ovulation. This means that your likelihood of getting pregnant will increase if you vomit within 4-6 hours after taking your daily pill.
• Diarrhea – Diarrhea is one way your body expels materials it deems harmful, such as bacteria, toxins, or spoiled food. Rather than taking these substances through your bloodstream, they’re passed through you—along with the hormones in your birth control. A single day of diarrhea won’t affect the efficacy of combination birth control pills (even if you’re not able to function, your birth control will!), but if your diarrhea lasts longer than 48 hours, or if you’re taking a progestin-only pill, your birth control’s ability to prevent conception may be impaired.

Bear in mind that women may have nausea as a side effect of OCPs, particularly in those first 3-4 months of a new regimen. If you just started a new type of pill and have been experiencing vomiting or diarrhea, you may have a higher likelihood of getting pregnant. You should monitor other physical signs of pregnancy like early pregnancy urine color as well.

#3 You’ve Been Taking Antibiotics

Most antibiotics won’t interfere with your birth control pill regimen, but two types that can make them less effective are:

• Rifampicin, which is used to treat tuberculosis and nose or throat infections.
• Rifabutin, which may be prescribed to treat ulcer-causing bacteria.

Both rifampicin and rifabutin cause your body to produce more enzymes, kicking your metabolism into high gear and breaking down your birth control much faster than normal. This means your body absorbs less estrogen and progestin. Since these two hormones work together to help prevent ovulation, reducing their levels leaves you with less effective birth control.

So, if you get intimate with a partner while on these types of antibiotics, you may have a greater chance of becoming pregnant.

#4 You’re Taking Medication for Your Mental Health

If you struggle with a mental health condition or epilepsy, you may be using medication to help your mental health or stave off seizures. While taking care of your well-being always comes first, two common types of medicine can impair the efficacy of OCPs:

• Anticonvulsants – Anticonvulsant, antiepileptic, or mood-stabilizing drugs may be used to treat epilepsy or bipolar disorder. One study showed that these types of medication can lead to lower levels of the estrogens in combination OCPs, and lower levels of estrogen mean less effective birth control.
• Herbal supports – St. John’s wort is a type of herb commonly used to combat depression or other mental health concerns. In some cases, this herb can reduce the concentration of hormones in your body and, in turn, your birth control pill’s efficacy.

#5 Your IUD Slips Out of Place

Hormonal IUD is among the most fail-proof types of hormonal birth control, but that doesn’t mean they’re the most fool -proof.

There are three reasons why it may still be possible to conceive with a copper or LNg (Levonorgestrel) IUD:

• Malpositioned IUD – To prevent pregnancy, an IUD must be properly inserted high up in the uterus. In rare cases, an IUD may be placed lower down, near the cervix, or it may slip from its original position on its own.
• Abnormal uterine structure – Every body is different, and in some cases, IUDs might not be well-suited to your particular uterine shape. If your uterus is unconventionally shaped, it may contract to shift the placement of your IUD, inhibiting its ability to prevent pregnancy.

Slip-ups can occur with both vaginal rings and IUDs, but the health consequences may be more severe in the latter case. Ectopic pregnancies, where an egg is fertilized outside of the uterus, are not uncommon when an IUD fails.

If you suspect you’re pregnant with an IUD, be sure to take a pregnancy test as soon as possible to keep your safety at the forefront and avoid any severe consequences. For more detailed guidance, read our article on taking out the IUD.

Early Signs and Symptoms of Pregnancy

If you have a slip-up, you may find yourself wondering if you’ve accidentally gotten pregnant. On the other hand, maybe you chose to stop your contraceptive in hopes of becoming pregnant. Whatever the reason, here are some signs to look out for that could signal it’s time to take a pregnancy test.

• Missed or late period
• Tender or sore breasts
• Nausea, vomiting, or diarrhea
• Fatigue, aching body
• Changes in appetite or sudden aversion to some tastes or smells

It is also important to note that implantation bleeding can occur during early pregnancy. This appears as light bleeding, which could be confused for a period especially if your periods lean on the lighter side.

Post-Birth Control: Your Fertility Timeline

Choosing to get off birth control and pursue the path to motherhood is a momentous decision that deserves its own round of applause (allow us— congratulations!).

Once you’ve made your decision, bear in mind that the timeline for restoring your hormones to their natural levels will depend on which type of contraceptive was used. This will affect how quickly your hormones will take to get back to “normal”. When getting off birth control, your body may experience some changes – so it is important to stay in touch with your doctor throughout the process if you observe any abnormalities.

If you decide to stop birth control, know your window to get pregnant will come back. The purpose of any time of hormonal contraceptive is to suspend your body’s ability to procreate—not put the kibosh on babies forever. If you’ve decided to shift gears into your life’s next chapter, it shouldn’t be long before your hormones level off and turn the page for you.

Kick-Off Your Pregnancy Journey With SneakPeek

For many newly-decided moms-to-be, preparing for life’s next stage means staying as informed as possible—from the bun in your oven to the baby in your bassinet. And taking a gender prediction SneakPeek Test can help you do just that.

The SneakPeek At-Home Early Gender Blood Test is the only DNA-based test that can tell you your baby’s gender as early as 6 weeks into your pregnancy journey! Plus, our test results are over 99% accurate¹ as shown in clinical studies, which is why it’s the #1 OBGYN-recommended gender test, trusted by more than 1 million moms.

Whenever you choose to start the path to motherhood, partner with SneakPeek to get the most out of your pregnancy and those precious early months with your little one.

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This post has been reviewed for accuracy by:

Priscilla Jeng

Priscilla Jeng is an accomplished digital marketing expert, currently leading as the Associate Director of Digital Marketing at Gateway Genomics, the parent company of SneakPeek. With over four years at Gateway Genomics, Priscilla has played a pivotal role in amplifying the company's mission to develop innovative genetic tests. Her proficiency in digital marketing and her comprehensive understanding of the genomics industry position her as a key contributor to SneakPeek's marketing endeavors.

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