21 weeks.... Your baby could measure about 10 inches from head to toe and weighs about three-quarters of a pound. The eyebrows and eyelids are fully developed and the fingernails cover the fingertips. Babies are more active at this stage, as they still have lots of room to move around. You’ll feel a lot more movement from your little one. You may want to start preparing for your baby's birth, by getting supplies together a little at a time.