This is actually the two week time span between your 'last normal menstrual period' (LNMP) and ovulation (or time of conception). The maturation process of the egg and the building of a new lining for the uterus take place at this time.
Before ultrasounds and other tools were available to doctors to help them deduce the date of conception, the date of your LNMP was the only way to determine a due date. Interestingly, these 14 days have remained in the ‘pregnancy calendar.' (So when you conceive, you are considered two weeks pregnant. Hey, it’s nice to have a head start, right?)
