If you have regular menstruation, with a cycle of about 28-30 days, and your last menstruation is on April 5, your due date will be January 12 of the following year. If your menstrual cycle is regular, the estimated date of delivery is as follows: the month of your last menstrual cycle minus 3 or plus 9, and the date plus 7, according to this method, your last menstrual cycle will be on April 5th, and your expected date of delivery will be on January 12th of the next year. If you have irregular periods or a long menstrual cycle, this method is not suitable for calculating your due date, but you need to verify the week of pregnancy according to the ultrasound examination of the early pregnancy, and then calculate your due date according to the results of the ultrasound examination. Therefore, if your menstrual cycle is regular and occurs once every 30 days or so, you can calculate your due date by the above method. If your menstrual cycle is irregular or long, you are advised to consult your doctor for help in calculating your due date.