How to calculate the due date

The expected delivery date refers to the estimated date when a pregnant woman will give birth. This date can be calculated based on the last menstrual period, the first fetal movement, or basal body temperature curves. Using the last menstrual period: A woman's gestational period is counted from the first day of her last menstrual period. To estimate the due date, add 9 months or subtract 3 months from the month of the last menstrual period, and add 7 days to the day of the last menstrual period. If the date of the last menstrual period is unknown, the expected delivery date can be estimated based on the date of first fetal movement. Typically, fetal movements begin between the 18th and 20th week of pregnancy. For first-time mothers, add 20 weeks to the date of the first perceived fetal movement to estimate the due date. The expected delivery date can also be determined using the basal body temperature curve. Counting from the last day of low temperature on the basal body temperature chart, the due date falls approximately 264 to 268 days afterward.