Your temperature when you’re fully at rest—called basal body temperature—rises slightly with ovulation. Measuring and recording your basal body temperature over several months can help you predict your most fertile days.
How it works
- Purchase a special basal body thermometer, available at most drug stores
- Record your temperature as soon as you wake each morning
- Note when your body temperature rises—this may indicate that ovulation is taking place
- Time intercourse with ovulation. Women are most fertile 2 to 3 days before their temperature increases and 12 to 24 hours after
Tips
- It’s important to take your temperature around the same time and under the same conditions each morning. Many factors can influence basal body temperature, including drinking alcohol or smoking cigarettes the night before, a poor night’s sleep, fever, or using the bathroom
- Because sperm can live for 3 to 5 days inside a woman’s body, having unprotected sex a few days before ovulation could achieve pregnancy
- Some women don’t experience a change in body temperature at ovulation. For these women, alternative methods will be more helpful