Can be successful with a motivated couple. Allows a woman to become informed about her reproductive cycle. Requires extensive instruction and following a number of steps to predict ovulation. Must be highly motivated. Difficult to use with irregular periods.
Illness can alter temperature.
Vaginal infections can alter cervical mucus changes. Chart temperature, cervical mucus changes, and menstrual calendar and refrain from intercourse during fertile period. Sperm live up to 5 days, the egg lives 24 hours. Therefore, most women are fertile a few days before to a few days after ovulation. There are also two new unique hand-held computer generated programs to help.