Conception

On around day 14 of a 28 day cycle a matured egg will burst through the lining of your ovary into your fallopian tube and start its journey to the uterus. When your partner deposits semen containing up to 600,000 million sperm into your vagina they travel up through the cervix and into the uterus, from here they travel to the fallopian tubes in search of the egg. Of the 100 sperm that reach your egg only one (usually) will break through the boundary and fertilisation occurs.

As the sperm penetrates the egg it disgards its tail and the head of the sperm (containing 23 chromosomes) and the nuclei (containing 23 chromosomes) of the egg are drawn together. Once they meet they combine to form a single cell with 23 pairs of chromosomes. Over the next 24 hours they multiply and divide to form two identical cells.

Over the next 4-5 days the cells continue to multiply and divide (roughly once every 24 hours). By the time they reach the uterus they have formed a cluster of around 12 to 16 cells. Now the outer shell that was the outer shell of the egg breaks and the cluster of cells floats free inside your uterus.

Around seven days after fertilisation the cluster of cells implants itself in the lining of your uterus where it continues to develop and grow for the next nine months.