Fertilization: Sperm Penetrates Egg. It takes about 24 hours for a sperm cell to fertilize an egg. When the sperm penetrates the egg, the surface of the egg changes so that no other sperm can enter. At the moment of fertilization, the baby's genetic makeup is complete, including whether it's a boy or girl.
Implantation bleeding is an early sign of pregnancy and only experienced by 1/3 of women. Discover when and what to look for as a sign of implantation. Implantation bleeding is an early sign of pregnancy and only experienced by 1/3 of women.
Implantation bleeding usually takes place on the 10-14th day after conception and occurs before the expected menstrual period. For instance, if you have conceived on the 5th day, you are likely to experience this type of bleeding between the 17th and 29th day.