If August 1st is the last menstrual period, use 8-3=5, 1+7=8, then the due date will be May 8th next year. Now there are many small programs to calculate the week of pregnancy and due date, after entering the last menstrual period you can know what day you are due and how many weeks pregnant you are now, very convenient. It is important to note that these apps are more accurate as they count out by date. The due date calculated by the formula method is affected by the change of days in each month, and there will be a difference of 1-3 days from the due date calculated by the APP. At present, some hospitals are still accustomed to use the due date calculated by the formula method in clinical practice, which causes confusion to many pregnant mothers. In fact, according to the definition of full-term pregnancy, births between 37 weeks and 41 weeks plus 6 are considered full-term births and are normal. As the time of conception may vary from early to late, and the start of labor is affected by various factors, not many babies are born on their due date, and most of them are born around their due date, such as 39 weeks plus, 40 weeks plus, etc. Therefore, pregnant mothers do not need to be torn and nervous. Regular checkups, counting fetal movements, and promptly seeking medical attention for any abnormalities. Another problem that bothers pregnant mothers is that many of them find that their weeks of pregnancy are always one week longer than the weeks given by the hospital. This is because pregnant mothers call the week starting from the first day of the last menstrual period the first week. In fact, the first day to the sixth day of the last period is called week 0, and from the seventh day onwards is called week 1, which makes a total of 40 weeks. The day of the 40th week of pregnancy is the expected date of delivery.