During ovulation, an egg containing the mother’s genes is released through the ovary wall and into the fallopian tube. It’s here that it meets the sperm containing the father’s genes that have made their way into the upper parts of the fallopian tube. This is where ovulation occurs as just one sperm successfully fertilises the egg, creating a whole new genetic blueprint for the baby. The combined sperm and egg are now called a zygote. The egg then starts to divide as it travels through the fallopian tube, towards the uterus. First two cells, then four, then eight, until they form a ball called a morula. This then forms a blastocyst about five days after fertilisation, which proceeds in the next day or two to embed itself into the soft lining of the uterus. It is now that pregnancy officially starts, although you technically date it from the first day of your last period.