Though this may be the first week a home pregnancy test confirms your pregnancy, it is incredible how many changes your little one has already gone through. By week 5, the embryo, now securely nestled in your uterine wall, will begin dividing into three layers of cells: the ectoderm, the mesoderm and the endoderm.

Ectoderm

The top layer of cells is called the ectoderm. The neural tube, which will eventually form the spinal cord and the brain, will begin to develop here this week. Skin, hair, nails and sweat glands all develop from this layer.

Mesoderm

The most impressive changes this week take place in the middle layer, called the mesoderm. Though your baby is only about the size of a grain of rice, her heart has divided into chambers and will begin pumping blood this week! Muscles, cartilage, bone, placenta and the umbilical cord will also all develop from this layer.

Endoderm

Your baby’s lungs, intestines, thyroid and pancreas will eventually develop from the endoderm.

Your body

Even though the first month of pregnancy is behind you, you may not even feel pregnant yet. It’s still too early in the pregnancy for you to have gained any weight. In fact, some women who experience morning sickness may have lost some weight in their first month of pregnancy.

Some early pregnancy symptoms also include tingling or soreness in your breasts, a darkening of the areola, the need to urinate more frequently, constipation and feeling more tired than usual. Some women even experience a metallic taste in their mouths!

If you do experience morning sickness (aka any-old-time sickness), some women find that eating 6 smaller high-carb meals instead of the standard 3 large meals helps. You should also avoid fatty foods and carry come crackers with you during the day to snack on to help ease the queasiness.

You may also want to invest in a jog bra as it may be more comfortable than the bras you are probably growing out of!