One of the first questions a pregnant woman hears is "when are you due?" (meaning "when are you expected to give birth?"). Because every woman is different and because it is often difficult to determine the actual date on which conception occurred, a due date is often an educated estimate.
Doctors have several methods for calculating your due date. The popular "Naegle's Rule" estimate is calculated by counting back three months from the first day of your last period, and then adding seven days. Many web sites offer calculators that automate the process of predicting your due date, based on the date of your last menstrual period. Keep in mind that while a normal pregnancy usually lasts between 38 and 42 weeks, these calculators are often set up to predict a pregnancy of 40 weeks (or the average between these expected extremes). Your own actual due date will happen when it happens, despite the best efforts of calculators everywhere.
Prenatal care (medical care delivered before you give birth) is important for the health of both mother and baby. This medical care can begin before you are actually pregnant. However, it really must begin as soon as you know you are pregnant in order to help insure that you have a healthy pregnancy. During your first prenatal care visit, your doctor will gather information about your disease history, personal habits (alcohol and drug use, exercise habits, the type of work that you do, etc.), family history (of multiple births, diseases, complicated pregnancy in close relatives, etc.), and any previous pregnancies, miscarriages, and/or abortions you may have had. It is also important that you share any complications that you may have experienced during previous pregnancies. As part of the initial exam, your doctor may perform an ultrasound test, and or blood tests. A pelvic exam is also sometimes performed.