DO NOT smoke a cigarette, eat or drink, or get up to go to the bathroom or to go find your thermometer before taking your temperature. Record the days you have sex by placing an arrow at the bottom of the column. Record the days of your menstrual flow with an X. Record mittleschmerz if you feel it. Also mark when your doctor performs any tests and what they are. Wash the thermometer with cool soapy water, rinse it, shake it down, and place it in its protective case beside your bed.
Some people prefer to use alcohol or disposable plastic thermometer protectors.
Repeat this procedure every day until your next period begins. Each month start taking your temperature on the morning your menstrual period ends. Take your charts to every doctor's appointment. Living with BBT Keeping the BBT chart is an inexpensive method for observing your menstrual cycle and hormonal system at work and an indirect method for ballparking when ovulation will occur. I've had some women tell me in total frustration that they're ready to flush their thermometer down the toilet.