Copulation usually causes the female to experience an orgasm, during which various muscular contractions draw a little of the semen into the uterus. From here a few thousand sperms may manage to swim up into the oviducts, and if a ripe ovum is present at the same time fertilization may occur.
How men make babies!
50 million sperm are discharged during just one ejaculation in a normal healthy male. It can take that many to begin the journey to the vagina, the cervix and on to the fallopian tubes. From all those millions of sperm only one or two will make it to a mature egg that is ready to be fertilized.
