Five weeks of pregnancy is actually three weeks of conception. The whole process of pregnancy is about 40 weeks, the egg and sperm combine to form a fertilized egg is the real start time of the whole pregnancy, and the actual time from the first day of menstruation to ovulation is about 2 weeks, so the correct calculation of pregnancy weeks is generally from the number of weeks after conception plus two weeks. However, in clinical practice, it is common for women who have regular menstrual periods to calculate the week of pregnancy from the first day of the last menstrual period to the current total number of days of pregnancy, and then divided by 7, so there is a difference of these 2 weeks. However, the pregnancy week is very much related to women’s regular menstrual cycle, and there is a big difference between individuals. If the menstrual cycle is too long or too short, it will affect the calculation of the pregnancy week and the expected date of delivery, so don’t worry too much, and it is recommended that you go to the Obstetrics and Gynecology Department of the hospital and follow the guidance of professional doctors.