Methods of projecting the expected date of delivery after pregnancy include projection based on the last menstrual period, projection based on ultrasound examination and projection based on the height of the uterine fundus. 1. Estimation based on the last menstrual period: This method is commonly used and is based on the number of months plus 9 (or minus 3) and the date plus 7 on the day of the last menstrual period. 2. Estimation based on ultrasound: If you do not remember your last menstrual period clearly, you can estimate the gestational age of the fetus based on the biparietal diameter, head and hip length, and femur length of the fetus measured by ultrasound and estimate the expected date of delivery. 3. Estimation according to the height of the uterine fundus: If the date of the last menstrual period is not clear and ultrasound examination is not available, the expected date of delivery can also be roughly estimated according to the height of the uterine fundus. This method is rarely used. After pregnancy, it is recommended to go to the hospital for consultation and estimate the due date under the guidance of the doctor, instead of doing it on your own, so as to avoid estimating the wrong due date.