Pregnant women must know how to accurately calculate the expected date of pregnancy. The expected date of delivery (EDD) is one of the biggest concerns for all expectant mothers. However, every pregnant woman’s physiological condition is different, so calculating the due date of pregnancy needs to be individualized. The following will give you a detailed introduction to the methods that pregnant women must know to calculate the due date of pregnancy. 1. Last menstrual period method The last menstrual period method is