Fertility Awareness

Family Planning, Natural, Natural Family Planning

What Affects the Test

For all methods

Fertility awareness methods will not work very well:

  • If they are not used consistently.
  • During stressful times or times when cycles are irregular, after a baby is born, after you stop taking birth control pills, or just before menopause.
  • If both partners are not willing to work together to use them.

Calendar (rhythm) method

The calendar method will not work very well if:

  • You have irregular, short, or long menstrual cycles.
  • You breast-feed for more than 6 months.
  • You supplement breast-feeding with bottle-feeding.

Basal body temperature (BBT) method

The BBT method will not work well if you:

  • Have a fever.
  • Take some medicines, such as aspirin.
  • Are traveling, having problems sleeping, or having other stress.
  • Use a different thermometer, take the thermometer out too soon, take your temperature at a different time of day, or take your temperature in a different way.

Cervical mucus method (Billings method)

The cervical mucus method will not work very well if you:

  • Use vaginal lubricants or douche.
  • Are breast-feeding.
  • Have a vaginal infection.
  • Are close to menopause.

Hormone monitoring

The results of hormone monitoring may not be correct if you do not follow the home ovulation kit instructions exactly.

Combined (symptothermal) method

Anything that changes the results of one of the methods also changes the results of the combined method.


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Author: Sandy Jocoy, RNLast Updated: March 21, 2008
Medical Review: Sarah Marshall, MD - Family Medicine
Kirtly Jones, MD - Obstetrics and Gynecology

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Topic Contents
 Test Overview
 Why It Is Done
 How To Prepare
 How It Is Done
 How It Feels
 Risks
 Results
Arrow PointerWhat Affects the Test
 What To Think About
 References
 Credits