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What BBT Changes Can You Expect During Your Cycle?
Your BBT is lower during the first two weeks of the menstrual cycle, prior to ovulation. The presence of the hormone estrogen keeps the BBT low. Typically it will range from 97.0 to 97.5 degrees Fahrenheit. Immediately following ovulation, progesterone "turns up the heat" a bit, and there is typically a rise of at least 0.4 to 0.6 degrees until the time of your next menstrual period. This temperature rise will let you know that ovulation has occurred.
How Can You Chart Your BBT?
Using either a notebook or graph paper, start recording on day one of your menstrual cycle -- the first day of your period. For each day, record your temperature, any reason for a variation in temperature (if applicable), if you made love that day, and if you were menstruating. This charting will not only be invaluable to you but will provide your health care provider with important information in helping you achieve your fertility goals -- of achieving or avoiding pregnancy.
What Factors Can Affect Your BBT?
Your temperature can be affected if you didn't get a good night's sleep, if you didn't have at least three hours of consecutive sleep after making love, if you have a fever or if you had an alcholic drink the night before.
How Reliable Are the Results?
The Fertility Awareness Method (FAM) is highly effective in achieving and preventing a pregnancy when used correctly. The more data you have, the more accurate your method will be. It is really best to chart your other two fertility signs, cervical fluid and cervical position, as well as chart your temperature. There are factors that can affect temperatures, but the trick is to learn how to see the forest through the trees and identify a pattern of lows and highs before and after ovulation, rather than focusing on any one particular temperature.