What is the conception period?

Pregnancy period in clinical is a unified calculation method, are based on the first day of the last menstrual period to calculate, such as if January 1 to menstruation, to February 10 is pregnant 41 days, is calculated in this way, not according to the time of cohabitation to calculate. Because in clinical, everyone's menstrual cycle is different, and the time of menstruation is not the same, so unified provisions, from the first day of the last menstrual period to calculate. If the menstrual cycle is not regular at ordinary times, it is recommended to check the B-ultrasound after the first pregnancy, see the size of the pregnancy sac, to calculate the time of conception, and then calculate the expected date of birth, so it is more scientific, so the time of the last menstrual period must be remembered, very critical.