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.
When Implantation Bleeding Occurs. According to MayoClinic.com, implantation bleeding occurs approximately 10 to 14 days after ovulation (when the ovary releases the egg). The range of time is broad because it all depends on how quickly the egg moves down the fallopian tube and attaches to the uterus.The duration of implantation bleeding varies.hen Implantation Bleeding Occurs. According to MayoClinic.com, implantation bleeding occurs approximately 10 to 14 days after ovulation (when the ovary releases the egg). The range of time is broad because it all depends on how quickly the egg moves down the fallopian tube and attaches to the uterus.