Our journey begins at the beginning of a cycle – an egg is released from one of the ovaries and down into a fallopian tube.

After sexual intercourse, sperm cells swim  from the vagina through the cervix until they reach their final destination of the fallopian tubes, where one sperm will fertilize the egg.

The fertilized egg (zygote) begins to divide repeatedly as it travels down the fallopian tube to the uterus. More and more cells form, until it becomes  a hollow ball of cells called a blastocyst.