Emergency contraception can be used to prevent an unintended pregnancy, for example after having unprotected sex or when a contraceptive method has failed (e.g. condom breaking). In certain circumstances when using Natural Cycles, you might consider using emergency contraception depending on where you are in your cycle.
What You Need to Know
- There are two options to choose from; the emergency pill or the copper IUD.
- Copper IUDs are the most effective method of emergency contraception and can be inserted up to 5 days after having unprotected sex1.
- The emergency pill should be taken as soon as possible after having unprotected sex. Some brands need to be taken within 72 hours and others within 120 hours2.
- Understanding how fertile you are, based on where you are in your cycle, can help you and your healthcare professional decide on the best method.
- To add this to your app: scroll down to the bottom of your ‘Add data’ page and select ‘More’ > Emergency contraception & Tests > Choose an option between the Pill or IUD, for the day you have taken this.
How Effective is it?
This depends on where you are in your cycle. There is a risk of becoming pregnant in the 6 days prior to and including ovulation (the fertile window). Emergency contraceptive pills contain either levonorgestrel or ulipristal acetate and work to delay ovulation2,3. They can be effective if taken before ovulation happens, during the most fertile time of the cycle. The copper IUD works by stopping implantation of a fertilized egg, it can be used at any point during the fertile window and for a few days after ovulation has occurred. Keep in mind that this is different to mifepristone (RU-486 or 'abortion pills') which act to terminate an established pregnancy, where implantation of a fertilized embryo has occurred.
You can use Natural Cycles to understand where you are in your cycle. In the ‘Graph’ view you can see where any given day is in relation to ovulation day.
Using Natural Cycles after Emergency Contraception
- Add this to your app by scrolling down to the bottom of your ‘Add data’ page and select ‘More’ > Emergency contraception & Tests > Choose an option between the Pill or IUD, for the day you have taken this.
- Continue measuring your basal temperature and entering it into the app as usual.
- Continue to abstain or use barrier protection during red days.
- Spotting or light bleeding can happen soon after using emergency contraception - this is not equivalent to your period.
- If your period is more than one week late after it would normally start you should take a pregnancy test.
When you enter that you have used an emergency contraceptive, the Natural Cycles algorithm will take into account how the additional hormones in the emergency contraceptive pill will affect your temperature measurements and cycle. The copper IUD is non-hormonal, so your temperature won’t be affected. It is common that the cycle in which you use emergency contraception might be slightly different, longer or shorter than usual for you.
Please read Natural Cycles' Instructions for Use for more information on how to manage your app following use of emergency contraception.
Using Natural Cycles requires that you abstain or use a barrier method, such as condoms, during intercourse on red days. Read more here.
This information is provided for educational purposes only and is not intended to replace the advice of your healthcare professional. Please consult your healthcare professional if you are unsure about using emergency contraception.
To read more about Emergency birth control and how it works, please read our blog post here: https://www.naturalcycles.com/cyclematters/how-does-emergency-birth-control-work/
- Cleland K, Zhu H, Goldstruck N, Cheng L, Trussell J. The efficacy of IUDs for emergency contraception: a systematic review of 35 years of experience. Hum Reprod. 2012;27:1994–2000.
- Glasier AF, Cameron ST, Fine PM, Logan SJ, Casale W, Van Horn J, Sogor L, Blithe DL, Scherrer B, Mathe H, Jaspart A, Ulmann A, Gainer E. Ulipristal acetate versus levonorgestrel for emergency contraception: a randomised non-inferiority trial and meta-analysis. Lancet. 2010;375:555–62.
- Richardson AR, Maltz FN. Ulipristal acetate: review of the efficacy and safety of a newly approved agent for emergency contraception. Clinical therapeutics. 2012 Jan 31;34(1):24–36.