In most cases, using a pregnancy calculator is incredibly simple. You do not need to put in any of your personal information.Rather, you are simply supplying dates and time frames. The first step is normally entering the date of your last menstrual cycle, or the date that your last period started. This gives the calculator a starting point to go from. From this point, your calculator can calculate several other bits of information for you. It may ask you for additional information, too, such as the average number of days in your menstrual cycle, from one period to the next.
From this information, the calculator will tell you when you are likely to give birth. The simplest form of this is to simply calculate 40 weeks from the date of your last period out. Conception generally happens two weeks after this date, which would provide you with a 38 week gestation period. The two additional weeks that bring the total pregnancy term to 40 weeks, are the two weeks prior to conception, which often confuses many people when calculating this information.
Be careful with the use of a pregnancy calculator, though. While they are accurate in the information that they provide, only about five percent of babies are born on their due date! Your baby should be born up to two weeks before or after your due date! Nevertheless, this tool serves as important tool in determining when you should get prenatal care.