The due date is calculated when you add 40 weeks or 280 days to the last date of your menstrual cycle. This is taking into consideration the fact that it happens to be a 28 day cycle. Pregnancy day’s calculator helps you to figure out when the baby is due and you can prepare well in advance. Take note of the fact that the due date is rated to be a mere estimate and each and every pregnancy happens to be a unique one. If the baby is due for arrival, it is bound to happen. Just talk to your healthcare provider regarding the exact due date of the baby as well. It is estimated that only 5 % of births are known to occur on the exact due date. Most babies are born on either side of the due date as well. If it is the case of a normal pregnancy it is going to be between 38 to 42 weeks.
Another important point of determining the due date is by Naegele’s rule. Here the birth of the child is predicted when you go on to add 280 days to the last date of your menstrual period. Pregnancy week by week pictures will throw more clarity on things as well. The base of this rule is that the cycle is 28 days long and the ovulation is going to occur on the 14th day. In fact the various other ways of calculation of the due date could work out to be more accurate as well.
As per modern statistics women are known to have their babies a few days after their average due date. Studies are of the opinion that the due date tends to be 2 to 3 days when this rule is applied. In this regard the better estimate would be 40 weeks or 3 days from the last date of your period
In case, if you figured out that you have conceived then the pregnancy days goes on to add 38 weeks to the date of conception as well. In fact, this calculation method works out to be more accurate than the LMP method and this is the entire more so if your cycles are on the irregular side as well.
This does bring us to the question on what is the exact date of conception. This is that point of time when the egg and the sperm meet. In case of others estimating the correct date of conception is not going to be an easy task at all. It is a well-known fact that sperm could reside in the body of a woman for 5 days and the ovum can live once 24 hours is over since it has been released. To sum it up you are likely to have a 6 day window where the chances of pregnancy are on the higher side.
Sperm could live in the vagina for 5 days and this means 5 days where you can become pregnant.