At this point the embryo begins to have a defining shape.  The placenta and umbilical cord are providing nourishment to the baby.  The first system to form, the circulatory system is now functioning with all four chambers of the heart present.  An ultrasound would show the first signs of a beating heart.

It’s easily possible to tell the difference between the head and tail at this point.  Depressions in the face that will become facial features are forming.  The eyes, ears, mouth and nose will become more pronounced and the small fold beneath will become the neck and lower jaw.  The arms and legs are becoming more formed and can be distinguished.  Fingers begin to grow.  A footplate begins to grow on the bottom of the legs. 

Your pregnancy may be affecting your emotions at this point.  Hormone increases may have you feeling a little out of whack.  This is normal and may be a first sign for some that they are pregnant.  Additionally, you may find yourself very tired during this time.  If you’ve seen your doctor, you’ve probably had a pelvic exam and possibly an ultrasound.

Related Weeks

Fetal Development – Week 4 | Fetal Development – Week 6

Fetal Development Week by Week – Week 5