Can you get pregnant while on the pill?

And yes, it IS true that there is a small chance that anyone could become pregnant using the pill, for a number of reasons.

However, this is true of all contraception – and then there’s the whole issue of trying to conceive after you’ve stopped taking it.

Pregnancy and the pill - what you need to know

In this piece, we’ll cover everything you need to know about your chances of getting pregnant while on the pill - and answer some of your most FAQs:

• Can you get pregnant while on the pill?
• Do I still ovulate on the pill?
• Why does the pill fail?
• If I’m still on the pill, how can I tell if I’m pregnant?
• Does the pill affect pregnancy tests?
• Can I get pregnant while switching contraceptives?
• Will the pill stop me getting pregnant longterm?

By clicking on one of the questions, you can skip ahead to read the answer – but we’d recommend giving the whole piece a read ?

Can I get pregnant while on the pill?

In a nutshell: yes, you can get pregnant while you’re on the pill.

A standard birth control pill is effective about 99.5% of the time if it is used 100% correctly.

Essentially, that means that even if you take it on time every day and follow the instructions to the letter, you still have a 0.5% chance of getting pregnant.

If you’re less diligent in following the instructions, the pill becomes less effective. Studies vary, but we’ve seen some show a user failure rate of over 5%.

That translates to 5% of women becoming pregnant while on the pill.

Do I still ovulate on the pill?

Nope, you don’t ovulate while you’re on the pill (no matter what kind of pill you’re on).

Suppressing ovulation is one of many ways the pill helps to prevent a pregnancy. The progesterone pill also does a triple whammy of pregnancy protection by thinning your uterus lining and thickening your cervical mucus.

Both of these help your chances of not becoming pregnant, should an egg get through and want to fertilise.

Why does the pill fail?

There are a number of reasons why the pill might not work. As we noted above, the most likely is that you’ve not been following the instructions and taking it daily, as instructed.

Your pill may also not be properly in your system if you’ve vomited or have severe diarrhoea, according to the NHS page on the combined pill.

(If either of these things happen to you, you should check the manufacturer’s instructions about doubling up with an alternative contraception for a period of time.)

It’s also important to make sure that the pill you’re taking works well with any other medication you’re on, such as antibiotics or migraine medication.

This is a conversation to have with your GP, when you’re initially prescribed the pill. Make sure they know what meds you’re taking.

There should also be an indication of what medications might affect the effectiveness of the pill in the instructions that come in the pill box.

Also, of course, there’s that 0.5% chance that you get pregnant anyway.

If I’m on the pill, how will I know if I’m pregnant?

Typically, you might realise that you’re pregnant when your period doesn’t arrive as usual – just as if you weren’t on the pill.

You may also experience some physical early signs and symptoms of pregnancy, even in the early weeks, such as tingling, sore or heavy breasts, and mild cramping.

Annoyingly, some of these can be symptoms of just taking the pill anyway. (Still, if you think you could be pregnant then take a home test as soon as you miss your period or arrange a test with your doctor.)

There’s no hard evidence to suggest that using the pill while pregnant could cause harm to the unborn baby – but that doesn’t mean it couldn’t, so it makes sense to stop taking the pill if you are pregnant.

Do contraceptive pills affect pregnancy tests?

You might be thinking, ‘Oh my God, it says I’m pregnant, but wait, doesn’t the pill have hormones in it that could affect test results?’

We’re afraid that the short answer is: no, the pill doesn’t impact the results of pregnancy tests.

The pill contains the hormone oestrogen and progesterone, but the pregnancy test is only looking to detect the pregnancy hormone, human chorionic gonadotrophin (HCG).

When to take your pregnancy test to get the right result is a whole other topic – which you can read about here.

Can I get pregnant straight after coming off the pill?

If you’ve come off the pill, and you're not trying to conceive, it’s likely you’re moving on to a different type of contraception.

Just know that it IS possible that you may be able to get pregnant soon after. A few of our MFMers have found themselves pregnant almost straight away, in fact.

That said, for many women it can take some time before you start ovulating again – roughly 6 months or maybe more.

If you're moving to a new kind of contraception, make sure you speak to your GP about how to remain protected during the transition.

Will the pill stop me getting pregnant longterm?

Many women start ovulating again 6 months after coming off the pill, and rest assured: there’s no evidence to suggest the pill does any affects your fertility negatively in the longterm.

"After discontinuing the pills, concerns arise about the possible negative effect of the pills on the menstrual cycle and the current ability to conceive,” says Dr Gorgy.

“These worries are not backed by scientific evidence."

The NHS backs this up, too: "It's unlikely that how long you have been on the pill will cause fertility problems. Some women conceive immediately after they stop taking the pill."

So, if you want to get pregnant in the future, just not right now, please don't worry ?

Have your say

Did you get pregnant while on the pill? Perhaps you got pregnant just after – or really struggled to conceive after using the pill for many years?

Please do share your stories in the comments below, on Instagram, or over on Facebook

Images: Getty Images

Read more:

• Male contraception - what is it and does it work?
• Is it possible to get pregnant while breastfeeding?
• No period but negative pregnancy test? Possible reasons