The buds are opening

Although there is still no outward sign, intense activity continues within the embryo. By the end of this week, your baby will be about the size of a bean. If you could look inside the uterus, you would see a bean-shaped structure with two tiny black dots at the upper end: the future eyes. The retina is already beginning to form. Nearby depressions smaller than a pinhead will become the ears, organs of hearing and balance. A primitive mouth and tongue are visible, and arm and leg buds appear. A thin skin layer forms, and there are 30-40 somites. The brain divides into three main parts. The thyroid continues developing and the lymphatic system starts forming. The heart fills with plasma and blood cells, and circulation begins. At this point, the two-part heart beats 150 times a minute, and Doppler ultrasound can let you hear it. Lung development continues, as do the gallbladder, stomach, intestines and pancreas. Blood from the placenta reaches the liver. The amnion surrounds the connecting stalk, which later remains as a structure called the umbilical vesicle. The arm buds are prominent, while the leg buds are just appearing. The embryo is now entirely inside the amniotic sac. Somites begin differentiating into muscles and bones.

There are no visible changes that reveal your pregnancy. Gaining or losing 1-2 kilograms is normal at this stage. Some early symptoms gradually diminish, although nausea and vomiting may increase, particularly early in the morning.