Here's a little tid bit about "charting". We use the sympto-thermal method. Obviously we are using this method to GET pregnant, not for prevention anymore!
The sympto-thermal method of natural birth control involves determining the few days out of a woman's menstrual cycles when conception can occur, and then avoiding sexual intercourse on those days. This method involves determining this fertile time in two ways: based on a woman's basal body temperature (it rises after ovulation) and by recording other fertility cues (such as mood and cervical secretions). The name "sympto-thermal" method, comes from body cues (i.e. symptoms) and a woman's temperature (i.e. thermal or thermometer).
How It Works: The Thermo Part
The sympto-thermal method requires that a woman take her temperature every morning before she gets out of bed and record the reading. Depending on where she is in her menstrual cycle, there will be slight variations in her temperature. These variations are most easily measured with a special thermometer that has a range of only a few degrees, known as a basal thermometer Before ovulation, the temperature is likely to be between 97.2 and 97.4 degrees F. After ovulation, it will rise by at least 0.5 degrees and is often above 98 degrees F. When the temperature stays elevated for at least three days, a woman may assume she has already ovulated. Intercourse for the rest of the cycle will not result in pregnancy. To determine the infertile time before ovulation, a woman needs to look at her pattern of previous cycles. Her last "safe" day is one week before the earliest recorded day of temperature rise, or 5 days after the first day of her period.
How It Works: The Sympto PartOvulation Method). Cervical mucus and firmness, mid-cycle cramping, breast sensitivity, and mood swings are all symptoms which give insight into the progression of a woman's cycle. With careful monitoring, it is not difficult to predict your fertile period, when intercourse is to be avoided. A blank NFP chart for recording these changes is available to view, download, or print.
Intercourse during the time before ovulation is less safe than the time after ovulation because sperm have been known to live up to six days. For this reason, some couples choose to have sex only after the fertile period. This practice, known as the post-ovulatory temperature method, is the most effective of all natural methods, with a failure rate of only 1% among perfect users. However, it is not recommended because it requires a very long period of abstinence.