Content

• Steps
• Tips
• Warnings

Basal body temperature (BBT) is your resting body temperature. If you are charting your BBT for getting pregnant or for birth control purposes, it is important to have accurate readings, and it is not as easy as you might think.

Steps

1. 1 Use a thermometer that is specifically designed to measure BTT readings. Do not use a standard thermometer as it is not accurate enough.
2. 2 Get enough sleep, if possible - sleep should be regular. Irregular sleep (including less than three hours of uninterrupted sleep) can lead to false readings.
3. 3 Take your temperature every day at the same time before getting out of bed. Set an alarm and keep the thermometer by your bed or under your pillow. Don't get up, don't walk, eat or drink anything, don't do anything at all (don't even shake the mercury thermometer) until you've measured your BBT (which should be measured at rest).
4. 4 Make a graph on graph paper or on a computer, with dates at the bottom and basal temperature on the side. You can search the internet for and print fertility charts, and you can subscribe to a fertility chart service.
5. 5 Look for a gradual or sudden rise in temperature (0.3 to 0.9 degrees Celsius). Fertility is high if your basal temperature rises within two to three days. So if you see a similar pattern from month to month, then those days when the temperature rises, this is the best time to conceive (or the best time to abstain if you are using this method for birth control).

Tips

• For a more reliable result, also observe changes in the cervical mucosa. At the beginning of the menstrual cycle, it is thin, sticky and dense; when ovulation is close, it becomes more slippery and plentiful, reminiscent of raw egg white. Checking the cervical mucosa can complement ovulation monitoring with BBT charts.
• The time you measure basal temperature should be as early as possible so that you can fall asleep again after that if you have an irregular sleep schedule.

Warnings

• The BBT chart is not 100% reliable as a birth control method and is best used in conjunction with other birth control methods.
• An increase in BBT can also be caused by emotional distress, stress, a cold or infection, jet lag, drinking alcohol the day before, or using an electric blanket.
• Avoiding intercourse during your fertile days will likely decrease your chances of getting pregnant, but it won't prevent the spread of sexually transmitted infections anyway.