Reviewed by

Uwe Porters - Mid-wife/Pregnancy & Postpartum Expert


Signs of Pregnancy While On The Pill

Reviewed by

Uwe Porters - Mid-wife/Pregnancy & Postpartum Expert

Birth control pills come close to being 100% effective at preventing pregnancy… but they aren’t perfect, despite what your doctor might have led you to believe. Even if you’re on the pill, you can still get pregnant. The main reason that the pill fails? Not taking it consistently. Illnesses that involve vomiting, other medications like antibiotics and improper storage at extreme temperatures can all also impact the effectiveness of the birth control pill. 

In this post, we’ll tell you more about how to make sure the pill is as effective as it can be and how to spot pregnancy symptoms while on the pill. 

Can you get pregnant while on the pill?

The short answer is yes. You can get pregnant even if you’re taking birth control. The pill is 99% effective BUT (and this is a big BUT) only when it is used perfectly

What exactly does perfect use mean? It means that you take the pill at the same time, every single day and never miss a day. We realise that life happens. Sometimes, even if you’ve been taking the pill for ten years, it’s still possible to forget. That’s why “typical use” is the more common way women use the pill. This means that you take the pill at slightly different times each day or accidentally miss a day here and there. But even with typical use, the pill is still 91% effective. 

These are high numbers but don’t get complacent. You don’t need to be a data scientist to see that there is still a chance that you can get pregnant, even with perfect use of the pill! 

Birth control pills most often fail if you’ve missed two or more pills in a row. This stops supplying your body with synthetic hormones and you could start ovulating. And, if you have unprotected sex when you’re ovulating, the chances of getting pregnant increase. 

Possible signs of pregnancy

Some of the symptoms of early pregnancy are similar to symptoms you might experience from the pill itself. So it can be confusing. Here are a few things to watch out for if you suspect you might be pregnant, even though you’re on the pill. 

Missed withdrawal bleed

If you use a combined pill where you take a one-week break, you usually have what’s called a “withdrawal bleed.” This is when your body mimics a period because of a hormone drop at the end of a cycle. But the pill can also mask the easiest sign of pregnancy to notice: a missed period! If you do not have withdrawal bleeding when you stop taking the pill, it could be a sign of pregnancy. 

That said, you could still have regular withdrawal bleeds even if you’re pregnant, so you may want to be on the lookout for other pregnancy symptoms while on the pill too! Read on… 

Nausea and vomiting

Another more obvious sign of pregnancy on birth control is morning sickness (which, by the way, can happen any time of day). If you find yourself suddenly feeling very nauseous or vomiting, pay attention. Sometimes, taking the pill on an empty stomach can cause you to feel a bit sick, so try taking your pill with food. If you still feel like you might see your breakfast coming back up, you may want to consider taking a pregnancy test. 

And, even if your test is negative, it’s important to think about a backup form of contraception. If you vomit within two hours of taking your pill, your body most likely has not had enough time to absorb it to be effective. 

Breast soreness / tenderness

This is a slightly more subtle sign of pregnancy while on the pill but if you are pregnant, you may find that your breasts become very tender to touch. Again, the pill can also cause this symptom, so pay attention to what is normal in your body. If your breasts are much more tender than usual, it might be time to grab a pregnancy test. 

Fatigue and headaches

If you’re pregnant, you might feel way more tired than usual. This is a very normal symptom in early pregnancy levels. But like nausea and breast tenderness, the pill itself can also sometimes make you feel tired and cause headaches. It all has to do with hormones and sometimes, it can be hard to rule out what could be the early signs of pregnancy and what might be a side effect of the pill. If you’ve missed two or more pills and you’re feeling much more tired than usual, you might be pregnant. 

Guud to know: The Side Effects of Birth Control

Changes in your belly

This may sound abundantly obvious, but if you’re pregnant, you will, eventually, start to notice changes in your belly. Notably, it will start to get bigger, especially between 12 and 16 weeks of pregnancy. Sometimes, pregnancy can also cause bloating and constipation which can make your clothes feel even tighter. 

If you’ve been pregnant before, you’ll notice this earlier as your belly has already stretched. 

Urinating more often than usual

Visiting the washroom more these days? Needing to pee more often is common at every stage of pregnancy. During the first stages, this is due to hormonal changes. Later on, it can be due to increased pressure on your bladder. Either way, if you’re running to the toilet more often than usual, think about your birth control use. Has it been perfect? Typical? Or… a little lazy? If it is the latter, you may want to take a pregnancy test. 


Does the smell of someone’s perfume suddenly make you feel a bit sick? Are you finding the smell of certain places, plants or food to be more intense than usual? You could have hyperosmia, a common condition in pregnancy that causes a heightened sense of smell! 


Similar to hyperosmia, if you’re pregnant, you may notice that your favourite foods and drinks suddenly taste different or even disgusting. This is called dysgeusia and it is a sudden change in your sense of taste likely caused by pregnancy hormones. It can cause you to taste certain flavours more intensely and hate food you normally love. It can also cause you to enjoy foods you normally hate! And sometimes, you might even notice a sour or metallic taste in your mouth even if you’re not eating anything. These symptoms are hard to miss, so if you notice that you suddenly hate your much-loved morning coffee and you’re craving egg salad sandwiches, take note. You might be pregnant. 

What to do if you suspect you're pregnant 

If you think you might be pregnant on birth control, the first step is to buy a home pregnancy test. 

If it’s positive, you should stop taking the pill right away. Don’t worry though if you’ve been taking the pill despite being pregnant. The hormones in the pill will not hurt your baby. 

Are you pregnant with an unplanned pregnancy and don't know what to do? Talk about it with your partner, a close friend or trusted family member. You can also always contact Fara (Belgium), Planning Familial (France) or Fiom (Netherlands). These organisations offer a non-judgemental and sympathetic ear as well as guidance and advice on your pregnancy choices.

Does the pill affect pregnancy tests?

The pill does not have an impact on the results of a pregnancy test. Pregnancy tests work by detecting a very particular hormone in your pee which is only produced when you’re pregnant. This hormone is called human chorionic gonadotropin (or hCG for short). 

Pregnancy tests are very accurate, however, you should consult your family doctor after a positive test to confirm you are pregnant with a blood test.  

How to support your pregnancy if you got pregnant while on the pill

Some women worry that if they get pregnant on the pill that their baby is at risk. Studies show that this is largely a myth and that the pill does not lead to birth abnormalities. 

However, for women who are trying to conceive, they often take folic acid to support both their bodies and their baby before and during pregnancy. If you got pregnant accidentally, it’s unlikely you were taking folic acid. But don’t worry! Start taking it as soon as you find out you’re pregnant.

How to prevent unplanned pregnancies

Even if you mess up here and there, typical use of the birth control pill is still highly effective to prevent you from getting pregnant. However, if you want to increase the effectiveness of the pill, here are a few things you can do:  

Keep the same routine

Take the pill every day at the same time. Try to do it at the same time as another daily habit, like brushing your teeth. Doing this maintains your hormone levels and decreases the risk of ovulation.

Don't skip placebo pills

If your pill brand contains placebo pills, don’t skip them. Even though these pills have no active ingredients, skipping them interrupts your routine and that can make it harder to build a consistent habit. It can also mean that you forget to start your next pack on time and this can increase the chances that you will ovulate.

Use backup protection

Some women choose to use another form of birth control alongside the pill, like a condom. This form of backup can provide some extra reassurance. 

Remember that some medications can reduce the effectiveness of the pill. If you’re taking antibiotics for example, you should use another form of protection for at least a month

Use emergency birth control if needed

We get it. We all make mistakes. If you’ve had unprotected sex and then realise you’ve missed a pill or two, you can ask a pharmacist for emergency birth control such as Plan B. 

You can take this up to five days after you’ve had unprotected sex but remember: the sooner you take it, the more effective it will be. 

Emergency contraception pills use synthetic hormones to prevent ovulation and implantation. The hormones in these pills may also prevent fertilisation by stopping your ovaries from releasing an egg. But remember: if you’re already pregnant, emergency birth control won’t end the pregnancy. They also won’t harm the baby. 

Thinking about quitting the pill? 

The pill is an amazing invention and, when used correctly, it can be extremely effective at preventing pregnancy. However, if you’re thinking about quitting the pill and perhaps returning to a natural cycle, we can help you. 

Here’s everything you need to know about quitting the pill and getting your cycle back on track. 

And, if you’re looking for other birth control options, check out our post here

Choosing the right contraception and everything to do with pregnancy can be stressful, especially if it wasn’t planned. Do you have questions? Need help? Or maybe just a friendly ear to listen? Talk to us. Just click on the Support tab on our website. 

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