This week your baby's brain is growing at a mind-boggling 100 cells per minute within a see-through skull. If you could peer inside, you'd see those tiny brain cells growing and growing and growing (about as quickly as you feel like yours are shrinking and shrinking and shrinking with your "pregnancy brain"!). More high points include:
Your baby's face is becoming more defined this week. A tiny mouth hole (which will be ready to wail before you know it!), tongue, nostrils and ear indentations are visible. His or her eyes are wide open, but he doesn't have irises (the colored part) yet.
Baby's arm buds are growing. At this point they look more like microscopic ping-pong paddles than arms. Baby's leg buds are also forming and will look like tiny paddles by the end of the week.
The umbilical cord—the connection between your baby and the placenta—is now visible.
Your baby is now between 1/3 and 1/4 inch long—about the length of a Tic Tac and about as heavy as an eyelash. While that sounds tiny, he or she is approximately 10,000 times bigger than at conception. Crazy, huh?