For a woman with regular menstruation, her last menstrual period is April 16th, and her expected date of delivery is January 23rd of the 2nd year. Pregnant women should project the expected date of labor according to the last menstrual period under the guidance of the doctor. Firstly, the week of pregnancy should be checked according to the gestational sac, the size of the buds or the length of the head and buttocks of the early pregnancy ultrasonography, etc., and then the expected date of labor should be projected. The due date is calculated from the first day of the last menstrual period, and the month needs to be subtracted from 3 or added to 9, and the number of days added to 7. Therefore, the due date for the last menstrual period on April 16th will be January 23rd of the following year. The expected date of delivery is based on the entire pregnancy, i.e. 40 weeks of gestation, but pregnant women do not necessarily deliver on the expected date of delivery, which may be earlier or later, so it is important to follow the doctor’s instructions to be on time for labor and delivery checkups, and at 28 weeks of gestation, only to strictly count the fetal movements to assess the safety and well-being of the fetus in the uterus. When abdominal pain, vaginal fluid, etc., should go to the hospital in a timely manner.