The question “how far along am I“ goes through most women’s mind after discovering that they are pregnant. It is important to determine how far along is your pregnancy (medically called the gestational age or estimated gestational age) in order to be able to calculate your due date as well as to evaluate your baby’s development. Two methods can be used to calculate the gestational age and answer the question “how far along am I“. The most commonly used method starts counting pregnancy from the first day of your last menstrual period. No, it is not the correct age of your developing baby if you are perhaps wondering because it starts counting the gestational age before the conception which usually occurs about two weeks after the beginning of your last menstrual period (when you ovulate). So if your doctor uses this method, you are not really pregnant 12 weeks and 3 days for instance but 10 weeks and 3 days.
Due to the fact that this system begins counting pregnancy before the actual conception, some health care providers use the estimated date of ovulation to calculate how far along are you as well as to calculate your due date. However, this method often does not predict the due date correctly either because not all women ovulate two weeks after the beginning of their last menstrual period.
It does not really matter which method your doctor uses to calculate the gestational age nor to estimate your due date. If he or she begins counting pregnancy from the day one of your last menstrual period, he or she will calculate your due date by adding 40 weeks (9 months and 7 days) to the first day of your last menstrual period. So if you began your last menstrual period on January 1, your due date is October 8. But if your doctor uses the estimated ovulation date to determine how far along are you, he or she will start counting pregnancy two weeks later. However, your estimated due date will be the same than in the first method because in this system, pregnancy lasts 38 weeks instead of 40 weeks.
No matter which method of gestational age calculation is used, you need to give your doctor the exact date of the beginning of your last menstrual period or at least as accurate estimation as possible. The more accurate date of your last menstrual period you provide the more accurate will be the estimated due date. But if you cannot recall the date of your last menstrual period, your doctor will calculate how far along are you by assessing the developmental stage of your baby.
The gestational age is not unimportant, especially for evaluating the baby’s development but it is not that important for calculation of the due date as you may think. The fact alone that only about 5 percent of women actually give birth on their due date says a lot. In addition, you are considered full term by the beginning of the 38th week of pregnancy or 36th week if pregnancy is counted from the estimated conception.