There is a particular process that the egg will follow from development through implantation, in which a union is formed with the sperm
First, an egg is developed in the ovaries and is then directed to the oviducts (uterine or fallopian tubes) where the egg then has the option of becoming fertilized with a sperm when a male climaxes during sexual intercourse.
When an egg becomes fertilized, its corona radiate and zona pelucida are essentially penetrated by a few sperm. A single sperm ultimately enters the egg and the nuclei bond together. After fertilization, the egg is now called a zygote, which will then divide to obtain the term embryo. This embryo will then make its way through the oviduct to the uterus where it will settle in the endometrium. Human chorionic gonadotropin will then be produced by the egg, which will ensure the endometrium of the uterus will remain intact to help create a temporary nine-month home for the developing embryo. The fertilized egg will then be housed in this "home" where it will grow, form, and develop for nine months into a fully developed baby.
The process of development begins when the zygote begins to divide after fertilization; ultimately, the original zygote is breaking away from its initial environment just as when a child is born it leaves the shelter and protection of the womb.
The next phase is morphogenesis in which the embryo is initially shaped through the rearranging of many cells. This process is similar to the initial birthing period when mom and dad need to change every aspect of their lives drastically so to make their home conducive to the habitat which is safe and protective for their new baby. The body is simply initially arranging the cells to prepare for the oncoming stages of development.
The third stage is differentiation in which the cells begin to develop into nerve impulses and muscles. This period is reminiscent of the period of time in which mom and dad have become more comfortable with the challenges involved in caring for their infant. The body is ready to accept and take on the new challenges involved in allowing for further development.
The fourth stage is growth in which the embryo divides and increases at a much faster rate. This stage is comparative to the active childhood of a child. The parents are comfortable with the child and can easily meet his or her needs or demands without any panic or lack of understanding. This is just how the body can quickly adapt to the rapid changes of the infant. Though in the end it will have developed into a much different shape than that which it originated it takes on these roles and challenges with the same grace and acceptance that a parent takes on the challenges that a child will then produce until he or she is grown.