Pregnancy refers to the state that a woman carries a embryo or fetus in the uterus. Mature egg and sperm meet and combine to form the fertilized egg, called fertilization. Fertilization is the beginning of pregnancy that is a sign of an individual life beginning, while the legal and medical definition holds that pregnancy is defined as the period between implantation of a fertilized egg (also called a zygote) in wall of the uterus and delivery or other termination.
Fertilization generally occurs within 12 hours after ovulation, fertilized egg once formed, that begins to develop. Human pregnancy lasts about 38 weeks from conception to birth, or 40 weeks from the time of the last menstrual to birth. Pregnancy is usually measured from the time of your last menstrual, which is called the “gestational age”.