Your embryo is now called a fetus, which means "offspring". She is only about 3.1cm long from crown to rump and weighs less than 4g. Even so, she’s busy swallowing and kicking. Each day more minute details start to appear, such as fingernails and peach-fuzzy hair.
Her vital organs – the liver, kidneys, intestines, brain, and lungs – are fully formed and functional, while her head is almost half the length of her entire body. Her forehead temporarily bulges and sits high on the head, but later will change into a more baby-like feature. If you could take a look at your baby this week, you'd be able to see the clear outline of her spine. Spinal nerves stretch out from the spinal cord. Your uterus (womb), which houses your growing baby, is now the size of a grapefruit.