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.
Signs Of Normal Implantation Bleeding And How Long It Lasts. Implantation bleeding occurs early in pregnancy when a fertilized egg buries its way into your womb lining. It occurs about 10 to 14 days post the conception period or after the egg gets fertilized. This is also usually the same time your menstrual cycle is expected.