Wouldn't it be wonderful if we could predict exactly when a baby will come? The birth of a baby is truly a surprise in almost every sense of the word. According to Dr. Gary Berger, an obstetrician at the Chapel Hill Tubal Reversal Center, determining a baby's due date, while based in science, is not entirely accurate. Although it is the most common way to determine a woman's due date, calculating from the date of a woman's last menstrual period is not the most reliable method. The most accurate method is to calculate from the date of conception. Knowing when you ovulate, and so the date of conception, will give you the most accurate due date possible.
Things You'll Need
- Ovulation predictor kit
- Basal body temperature thermometer
Determine your ovulation date. If you are able (meaning not already pregnant), find out when you normally ovulate by keeping your basal body temperature or purchasing an ovulation predictor kit at your local pharmacy.
Use your knowledge of your ovulation dates to determine your date of conception. If you are trying to conceive, keeping track of these dates will help you eventually determine a more accurate due date once you become pregnant.
Add 38 weeks. A pregnancy is generally considered full-term 38 weeks after the date of conception. If you know the date of conception, adding 38 weeks (266 days) will give you the most accurate date possible. Most conception dates are not known, however, so the date of the first day of a woman's last menstrual period is used and 40 weeks are added to it, as most women ovulate approximately two weeks after their period begins.