Menu

Can You Get Pregnant While on the Pill?

by

About This Article

Zoom Baby has provided pregnancy, ovulation and fertility testing guidance for over 20 years. This article explains how the combined contraceptive pill prevents pregnancy, how effective it is and what can reduce its protection.

Published: 20 January 2024 | Last Updated: 13 September 2026 | By: Anthony Cunningham

The combined oral contraceptive pill, more commonly known as ‘the pill’, is a popular method of contraception. Some types are taken for 21 days followed by a 7-day break, while everyday pills and tailored regimes are also available. The hormones in the pill work to prevent ovulation and thicken cervical mucus to help stop sperm reaching an egg.

But can you still get pregnant even if you’re taking the pill correctly? Let’s take a look at how effective the contraceptive pill is and what can cause it to fail.

Contents

How the contraceptive pill prevents pregnancy

The pill contains synthetic versions of the female hormones oestrogen and progestogen. It works in several ways:

  • Prevents ovulation – stops your ovaries from releasing an egg each month for fertilisation
  • Thickens cervical mucus – makes it harder for sperm to reach the womb and fertilise an egg
  • Thins the womb lining – can prevent implantation of a fertilised egg

When taken properly, these actions work together to stop pregnancy happening.

Typical and perfect pill use

No method of contraception is completely effective, so pregnancy remains possible while taking the pill. With typical pill use, around 9 women out of 100 will get pregnant in a year of use. However, with absolutely perfect use, fewer than 1 woman in 100 will get pregnant in a year.

Typical use accounts for common human errors like forgetting to take your pill or occasionally taking it late. Perfect use means taking the pill consistently, at the same time daily, without ever missing one.

In real life, achieving perfect pill use can be challenging. But you can maximise your chances by setting a daily reminder and linking it to an existing routine like cleaning your teeth. If you find yourself regularly missing pills or taking them at different times, speak to your doctor about switching to a more appropriate contraceptive option for your lifestyle.

What to do if you miss a pill

If you miss a combined pill, what you should do depends on the type of pill, how many pills you have missed and where you are in the pack. Read the patient information leaflet supplied with your pills or ask a pharmacist for advice.

You may need emergency contraception if you have had unprotected sex. Speak promptly to a pharmacist, sexual health clinic or GP, or call NHS 111, because the combined pill can affect how some emergency contraception works.

Can other medications affect the pill?

Some medications can interfere with how the contraceptive pill works when taken at the same time. These include:

  • Some medicines used to treat tuberculosis, epilepsy or HIV
  • Griseofulvin, an antifungal medicine
  • Lamotrigine, a mood stabiliser
  • St John’s wort, a herbal remedy

Always check with your doctor or pharmacist before taking any new medications alongside the pill. You may need to use additional contraception while taking that medicine and for a short time after.

What if you’re sick while on the pill?

If you vomit within 3 hours of taking your combined pill, it may not have been fully absorbed. Take another pill as soon as possible and follow the instructions supplied with your pill. Some brands have different advice.

Severe diarrhoea lasting more than 24 hours can also reduce protection. Continue taking your pills, check the patient information leaflet and use additional contraception if instructed.

5 x Regular Pregnancy Tests

If you think your contraception may have failed, a home pregnancy test can help you check. These Zoom Baby pregnancy test strips detect hCG in urine and include plain-English instructions.

View 5 x Regular Pregnancy Tests

Considering alternatives to the pill

There are many contraceptive options besides the pill, including:

  • Contraceptive implant – inserted into your arm and lasts 3 years
  • Contraceptive injection – an injection every 8 to 13 weeks
  • Intrauterine system (IUS) – inserted into the womb and can last 5+ years
  • Contraceptive patch – a patch on your skin changed weekly
  • Vaginal ring – inserted monthly and left in place for 3 weeks

If taking a daily pill is proving problematic, one of these longer-acting reversible contraceptives may suit your lifestyle better. Discuss your options at your next sexual health screening or contraceptive review appointment.

Additional information

  • With typical use, around 9 out of 100 women will get pregnant using the pill over 1 year
  • Take your pill consistently and follow the instructions supplied with your particular pill
  • Speak to your doctor if you regularly miss pills or take them late
  • Consider longer-acting alternatives like the implant if the pill doesn’t suit your lifestyle

About the Author

Anthony Cunningham, BA (Hons), MA, is a UK-based fertility testing expert and editor with over 20 years’ experience running Zoom Baby, a trusted source for accurate pregnancy, ovulation and fertility tests and testing guidance. He creates clear, evidence-based articles using NHS guidance, professional fertility resources, and conception planning best practices. Where possible, content is reviewed by fertility specialists and healthcare professionals to enhance accuracy and reliability, helping readers make informed testing decisions.

Medical Disclaimer

This article is for general information only and is not a substitute for professional medical advice, diagnosis or treatment. If you have concerns about your health or symptoms, speak to your GP or another qualified healthcare professional. In an emergency, seek urgent medical help.

You May Also Like