According to the usual way pregnancy is calculated, you are considered four weeks pregnant.At least we obstetricians call it four weeks, because we count from the last regular menstrual period.The forty weeks of pregnancy take up nine months according to the Gregorian calendar.It is no coincidence that the average menstrual cycle lasts twenty-eight days.The due date is referred to as the estimated date of confinement (EDC).This is a throwback to the days when a woman was “confined” to bed and home for a period of time after birth until convalescence was complete.The importance of the due date to the obstetrician is emphasized when your baby chooses a date remote from the calculated due date.Worries about going beyond your due date apply as well.
LMP (last menstrual period) is the only observable event from which to calculate a pregnancy without the aid of ultrasound.
But it’s not a due “date”, because there is too much variation in the general population.
Since term is anywhere from 38 to 42 weeks, it’s really a “due month.” Yes, there are those early birds that like to come early, pushing themselves into the world as premature babies if they come before 37 weeks.
The correct answer to the question of when your baby is due is your due date give or take a couple of weeks.
FAST FORWARD Term is usually designated as the day forty weeks after the first day of the last regular menstrual period.