The process of natural conception
Human reproduction is the result of the union of an egg (produced in the ovary) with a sperm (produced in the testis), giving rise to an embryo that will develop in the uterus into a fully grown baby.
After sexual intercourse, the sperm are deposited in the vagina, from which they begin their journey from the outer cervical opening (the gate to the internal female reproductive system which is open and accessible during the fertile days) and progress through the cervical canal and the uterus reaching the fallopian tubes.
The fallopian tube also receives the newly ovulated egg via the fimbria, and is the site where the egg is fertilised by the sperm. The fertilised egg (called zygote) is transported down the fallopian tube for the next 5-6 days during which time it divides into 2, 4, 6, 16 etc cells.
When the embryo reaches the uterus it has developed into a blastocyst (60-120 cells), which is capable to implant in the endometrium (conception) and continue its further development.