During ovulation the finger like end (fimbriae) of the fallopian tube gently sucks the leading egg off the ovary and guides it inside one of the fallopian tubes. It is here that the magic occurs. If the timing is right, a few hundred of the healthiest sperm will be swimming through the cervix up towards the fallopian tubes at this moment. Of them, just one (if any) has the right stuff to beat the others to penetrate the egg that is nearly 600 times its size. Once the sperm penetrates FERTILIZATION has occurred and the two fuse together to form an embryo.
The work is far from done. Now it’s the embryos turn to take a four to five day journey all the way to the uterus, dividing and dividing en route. If it gets there and if the endometrium (lining of the uterus) is sufficiently thick enough, then and only then, will the embryo implant into the wall. The time elapsed is about seven to eight days. If IMPLANTATION occurs and the right environment surrounds the embryo it continues to develop into a fully fledged fetus ready for delivery forty weeks later.
If any part of the processes goes wrong, either fertilization or implantation, the thick endometrium gets a signal to shed and menses occurs four days later. And the cycle begins again!
This is just a simple explanation. It sound treacherous, exciting, exhausting and remarkable- and it is truly amazing!