Around 14 days before a persons' period is due, their ovaries release an egg ovum. This is when someone is most likely to get pregnant. When a person with a penis is n ot wearing a condom ejaculates or cums inside a vagina, millions of sperm are released into the vagina. The sperm swim into the womb and fallopian tubes. If just one sperm implants itself into the released egg, fertilisation occurs.
What Happens to Sperm Once They're Inside a Woman?
Pregnancy | Get the Facts
There are approximately million sperm in each human ejaculation, but only about 2 million sperm make it into the cervix. Out of the approximately 2 million sperm entering the cervix, only about 1 million make it into the uterus. The rest are stopped by gooey mucus, or swim into dead-end channels inside the walls of the cervix. Out of the approximately 1 million sperm that enter the uterus, only about 10, make it to the top of the organ. The rest are attacked and absorbed by white blood cells, which start to appear in force as soon as sperm enter their defensive perimeter. Out of the approximately 10, sperm cells that make it to the far end of the uterus, only about 5, turn in the right direction. Out of the approximately 5, sperm that enter the uterotubal junction —a twisty space connecting the uterus and the oviduct—only about enter the Fallopian tube.