So the normal gestational period is defined to be "from the first day of the woman's last menstrual cycle to the current date.".
Why is that? Wouldn't the more natural definition be "from two weeks after the first day of the woman's last menstrual cycle to the current date"?
I realize that the first day of the last menstruation is a definite date that can usually be measured, but between that date and the date of conception, normally 14 days, the woman is actually not pregnant. Why are two weeks of non-pregnancy included in the definition of the period of gestation?
This would change the meaning of the normal length of pregnancy from 282 days to 268 days.