How long is a normal pregnancy? And how normal is normal anyway? What is normal? The latter question is an indication that it is rather hard to define normal in relation to the time of a pregnancy since multiple pregnancies may be normal all the way but will not last the full gestational period. Most multiple pregnancies are born preterm. In this respect, we will refer to a normal pregnancy as being the single-fetus pregnancy since it is the most common type of pregnancy. A pregnancy that is normal will last the full human gestational period of nine months of 36 weeks. Some may extend to 40 weeks and will not be any less normal than others although any more extension can lead to a lot of complications. The pregnancy period is divided into three trimesters of three months each. The first trimester is the most crucial when the baby develops most of its features. In the second trimester, the baby’s facial features will be visible and movements will be felt by the mother as well. The third trimester baby is fully developed and preparing for labor. It turns upside down although this is not the case in breech births.