Although the birth control pill is one of the most common methods of birth control, it is still only 93% effective with typical use (versus perfect use). That means that out of one hundred women on these oral contraceptives, seven will typically become pregnant within a year.
Are you concerned that you may have become pregnant while on the pill? Here’s how to determine whether or not you’re pregnant, why women get pregnant on birth control, and what to do next.
Can I get pregnant on the pill?
It is possible to get pregnant while on the birth control pill. Have you skipped taking the pill a couple days here and there? Are you sensing that something’s not quite normal with your body? You may be pregnant if you’re experiencing some or all of these early signs of pregnancy:
- Missed period
- Food aversions
- Breast tenderness
- Cramping and spotting
- Weakness and exhaustion
- Mood swings
- Frequent urination
- Stomach issues
- Dizziness
- Acne
- Weight gain
The most telling sign of pregnancy is a missed period. The only way to be 100% sure that you’re pregnant is by taking a pregnancy test sometime after the first day of your missed period, or when you think your period should have started.
Use our She Might Pregnancy Test Calculator to determine when you should take a pregnancy test for the most accurate result.
How did I get pregnant on the pill?
The pill is one of the most effective forms of birth control—if used correctly. However, most women don’t use it exactly as prescribed. This is the difference between “perfect” use and “typical” use. When I was on the pill, I can remember frequently panicking after forgetting to take my daily dose.
How does the pill work?
To understand how you got pregnant while on birth control, let’s take a look at how the birth control pill works.
There are two main forms of the birth control pill: the combination pill and the progestin-only pill.
The combination pill contains synthetic forms of estrogen and progesterone, two important hormones that are involved in your menstrual cycle and reproductive system. An alternative pill, called the “mini-pill,” only contains progestin and is primarily for women who should not take estrogen for health reasons.
When taken according to instructions (at the same time every day), the pill has three ways it is thought to prevent pregnancy:
- It interrupts the hormonal feedback loop that triggers ovulation, stopping it from happening.
- Should breakthrough ovulation still occur, the pill thickens and dries your cervical mucus, creating a more hostile environment for sperm traveling to the eggs.
- And finally, should breakthrough ovulation and fertilization occur, the pill may thin the uterine lining, making it harder for a fertilized egg to implant in your uterus.
Why does the pill fail?
No birth control works all the time, but the pill is 99% effective if used perfectly. That means only one in every hundred women who use the pill perfectly will get pregnant every year.
If you, like most women, occasionally forget to take your dose on time, you can expect the pill to be 93% effective. That gives you a 7% chance of becoming pregnant within a year.
Here are other circumstances that can cause birth control pills to be less effective:
- Taking pills past their expiration date
- Your pills being exposed to temperature/humidity fluctuations
- Interaction with certain other medications (Antiviral HIV medication, some antibiotics and antifungals, epilepsy and migraine treatments, St. John’s Wort, mood stabilizers).
- Vomiting or diarrhea
- High BMI
But I got pregnant using birth control and condoms!
Pregnancy can happen while using multiple forms of birth control. Although combining a condom with the pill greatly decreases your chances of pregnancy, it doesn’t eradicate it. If you got pregnant using birth control and condoms, chances are the condom tore during use.
I’m pregnant…now what?
Take a test. If you think you may be pregnant, now is the time to take a home pregnancy test. Use She Might’s pregnancy test calculator to figure out when it is best for testing. Be sure to take the test properly at the appropriate time to ensure accurate results.
Stop taking the pill. If you’ve taken a pregnancy test and confirmed you are pregnant, stop taking the pill. While you may still be making a pregnancy decision, and research hasn’t indicated that the hormones in the pill will harm the fetus, there is some anecdotal evidence that it might contribute to problems like low birth weight and urinary tract issues.
If you were faithfully using birth control before you discovered your pregnancy, try not to worry. But, there’s also no reason to continue with birth control until your pregnancy is over.
Moving forward with options
Remember, thousands of women get pregnant on the pill every year, so you’re far from alone.
Unexpected pregnancies, regardless of the circumstances, can be disorienting and stressful. That’s why we’ve created resources to help you process your positive pregnancy test and your pregnancy options, with clarity, with community, and without fear.
As you contemplate your next move, make a whole-hearted decision using our 5-minute Clarity Quiz and She Might Coaching resources. We’re here to make sure you don’t have to process your pregnancy alone.