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.
Blood from implantation does not clot, and it will be on and off. Women can expect this to last hours, or up to 4 days. Spotting is most common with implantation. 2. Implantation Cramping. One of the most common implantation symptoms is cramping. These cramps are often more mild than period cramps and should not be so bad that you wince over in pain. Mild in nature, these cramps will only last a short period of time with many women experiencing them for just 5 minutes. If you feel any severe pain, itâs a smart choice to see a doctor.