Particularly in the early stages, symptoms of pregnancy can vary among women. And while the absence of menstrual periods is the classic and hallmark pregnancy symptoms, there are many other changes in the body, even during early pregnancy that result in characteristic signs and symptoms.
A missed period is the hallmark sign of pregnancy. Missing a menstrual period is typical, although many women report having light bleeding or spotting bleeding at the time of the expected period, a phenomenon that has been referred to as “implantation bleeding.” If this bleeding occurs and is mistaken for a light menstrual period, it’s possible for a woman not to realize that she is pregnant.
Pregnancy is caused by the fertilization of an egg by sperm and implantation of the resulting fertilized egg in the uterus.