The basal body temperature (BBT) is a person's at-rest
temperature. Women can track their BBT to find out when they are
ovulating. With this timeline, a woman can learn when
she is most and least likely to become pregnant.
When am I most likely to become pregnant?
About 2
weeks before your period you will
ovulate
, which means one of your ovaries has released
an egg. You are most likely to get pregnant on the day of ovulation and the
five days before it.
When am I least likely to become pregnant?
Your egg is fertile for about 12 to 24
hours after you ovulate. Avoiding sex until several days after ovulation may
help you prevent pregnancy. Keep in mind that your cycle can change, making it
hard to know when you are ovulating. Some women use this information as a form
of birth control. It is not very reliable for preventing pregnancy.
How can I predict when I will ovulate?
Your body temperature dips a bit just before your ovary releases an egg.
Then, 24 hours after the egg's release, your temperature rises and stays up for
several days. Before ovulation, a woman's BBT averages between
97°F (36.1°C) and
97.5°F (36.4°C). After
ovulation, it rises to
97.6°F (36.4°C) to
98.6°F (37°C).
You can track your cycle by taking your BBT every morning. Take your
temperature at the same time, every day before getting out of bed. Next, record
the results on a chart. If you have a somewhat regular cycle, the chart will
help you predict when you will ovulate next.
What do I need to take my basal body temperature?
The change in
your body temperature is very slight so you need to use a special thermometer.
You can use a regular digital thermometer, or buy a basal thermometer. A basal
thermometer shows you the temperature in tenths of a degree. This allows you to
note tiny changes in body heat. This thermometer is faster and more exact than
a regular thermometer.
You'll also need a chart or graph. You can
make one, buy one, or download a chart over the Internet. Some basal
thermometers come with a chart.
Where can I get a basal thermometer?
You can find a basal thermometer or
digital thermometer in a pharmacy or in the pharmacy section in many grocery
stores. You can also find kits that include materials for measuring and
charting BBT. These items are low in cost.