Sign in to your account

Don't have an account?

Create an account
This website uses cookies to ensure you get the best experience on our website. Learn more
Black medical doctor in a white coat and red stethoscope examining a patient on a ward. Our doctors on askawayhealth have years of clinical experience to provide top notch care.

Need to check your symptoms?

Use our symptom checker to help determine what your symptoms are and to ensure you get the help you need.

Check your symptoms


Request a reset

Don't have an account?

Create an account


Reset your password

Don't have an account?

Create an account


Unexpected Pregnancy Explained: Understanding Contraceptive Challenges

April 19, 2021

How do you end up with an unexpected pregnancy after taking every possible precaution?

Here’s a troubling enquiry from a couple who hit a snag after emergency contraception failed…….

Hello doc, How on earth is it possible for someone to get pregnant after using a condom during sex and taking Postinor-2 immediately after?

Well, this is not an unusual enquiry and many couples have become ‘caught out’ as a result. But let’s take a closer look at Neither of these two methods is 100% effective in preventing pregnancy.  

In fact, no method is absolutely effective – except abstinence.

Pregnant Despite Using Condoms

Condoms (the male version) are reported as being around 82% effective when used properly – and most times, they are probably not used properly.

A Condom is essentially a barrier that prevents the sperm in the man’s ejaculate (cum) from travelling into the woman’s womb.

Generally, condoms are packaged in individual wrappings for protection and to maintain their durability.

They could be torn when being opened (during sexual frenzy) or burst/ripped during use – especially if they are old or not properly stored before use.  

They should be worn early during sexual activity and before vaginal penetration – not just when about to ejaculate.

Some men feel the condom takes the pleasure away from sex and are not keen to use it.

Condoms are excellent for preventing sexually transmitted infections (STIs), which other forms of contraception cannot. The are less effective but still better than nothing for avoiding an unexpected pregnancy.

But because a lot of their effectiveness relies on the user, the risk of failure when it comes to preventing pregnancy is high. These are some of the reasons you can get pregnant despite contraception with condoms.

Read – Remedy for a Closed Cervix?

Pregnant Despite Contraception

Why Emergency Birth Control is not FoolProof

Postinor-2 is an emergency contraceptive pill that is effective in delaying ovulation (i.e. the release of a woman’s egg).

Postinor-2 contains Levonorgestrel (LNG), a man-made progesterone drug usually meant to be taken as soon as possible following sexual intercourse; with a second dose 12 hours after the first.

Its effectiveness depends on the time of the woman’s cycle it is taken.  

For LNG pills it is most effective usually when taken immediately after sex up to 72 hours after intercourse.

This must be during the time just before the middle of her cycle or the first 11-12 days after she completes her menstrual flow/period.

If the lady has ALREADY ovulated in that cycle – so it’s more than 12 days or more after she completed her period – Postinor-2 may not work.

This generally applies to women with a regular 28-day cycle. Many women, however, do not have regular cycles. This means their monthly periods may be less or more often than every 28 days.

Additionally, even if you have a 28-day cycle, the ovulation date is usually estimated. Using ovulation apps or monitoring with ovulation kits will not give you an exact time for ovulation.

Another effect of Postinor-2 is that it can interfere with the movements of the sperm and prevent fertilisation that way.

This is a minor effect, though, and we do not know how much of the pill’s success can be linked to this.

Essentially, the pill may have failed because she’s already ovulated; or taken after the 72 hours window period when it is MOST effective.

Pregnant Despite Contraception

Risks of getting pregnant despite Emergency Birth Control

So if a lady has already ovulated when she has intercourse, taking Postinor-2 could prevent the sperm from fertilizing the egg and prevent pregnancy.

On average, Postinor-2 has an 85% chance of preventing pregnancy.

If taken within 24 hours (recommended), there is a 95% chance of preventing pregnancy.

If taken after 48-72 hours, there is a 58% chance. 

It is not known whether it is effective if taken more than 72 hours after unprotected intercourse.

Which Birth Control Methods are Most Effective?

The most effective way to avoid an unexpected pregnancy outside of abstaining from sex is the use of regular hormonal contraception.

The current methods with the best effectiveness rates (99%) are:

  • the Implant,
  • Intrauterine device or
  • Sterilisation.

Key Takeaways

In line with your fertility plan, what contraceptive would you rather use: Postinor 2, implant or intrauterine device?

To prevent an unexpected pregnancy, you should abstain until you are ready or choose or reliable form of birth control.

More Reading

Editing By AskAwayHealth


All AskAwayHealth articles are written by practising  Medical Practitioners on a wide range of healthcare conditions to provide evidence-based guidance and to help promote quality healthcare

The advice in our material is not meant to replace the management of your specific condition by a qualified healthcare practitioner.
To discuss your condition, please contact a health practitioner or reach us directly

Image Credits – Canva

Share this blog article

On this page

Let us know what you think

Want to know how your comment data is processed? Learn more

Access over 600 resources & our monthly newsletter.

Askawayhealth 2023 grant recipient from European Union Development Fund

Askawayhealth, 2023 Award Recipient

Our educational content meets the standards set by the NHS in their Standard for Creating Health Content guidance.

Askawayhealth aims to deliver reliable and evidence based women's health, family health and sexual health information in a way that is easily relatable and easy for everyone to access.

Askawayhealth symptom Checker tool image

Utilize our complimentary symptom checker tool to gain more information about any uncertain symptoms you might have.