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.
Some women also experience light bleeding, but this should not be heavy or bright red like your regular period (implantation bleeding is usually pinkish or light brown). Implantation discomfort and/or bleeding will usually occur five to 12 days after ovulation. The pain you are experiencing should never be severe; if it is, or if you experience fever, chills, or heavy vaginal bleeding, call your doctor right away.