At week seven of pregnancy the baby is between ¼ – ½ inches in length. On ultrasound you can see a strong heart beat. You can probably differentiate the head from the body on the fetal pole on ultrasound at week 7. The baby is starting to make arm and leg buds at this stage. There also may be a yolk sac visible at this stage on ultrasound. This is a round area toe the side of the fetal pole. The yolk sac gives nutrition to the baby as the placenta is forming.
At week 7 the umbilical chord is formed. This is the structure that brings blood between the baby and the placenta. This means that the baby is receiving oxygen and nutrients from the mother’s blood through the placenta. The baby has circulatory system that moves blood around the baby as well as to the placenta and back again.
HCG is the pregnancy hormone and it is rising fairly rapidly at week 7. HCG is responsible for the typical symptoms of pregnancy. These symptoms include breast swelling and tenderness, nausea, vomiting, and fatigue. It is common to have some or all of theses symptoms in varying degrees. For some women they can be severe, most women experience them more mildly, and some lucky women do not experience them at all. Most women will find the symptoms go away by the end of the first trimester of pregnancy. Do not be worried if you do not have the symptoms, it does not mean anything is wrong with the pregnancy.
It is very common to experience spotting at this stage in pregnancy, particularly after intercourse. This is nothing to be alarmed about and does not mean that you are going to miscarry. Heavy bleeding or significant pain does need to be evaluated, but spotting is quite common and generally not dangerous or worrisome.
This is a good time to make an appointment with your obstetrician if you have not already. Also you should be taking a daily prenatal vitamin. You do not need to wait to see the doctor to start your prenatal vitamin. The over-the-counter prenatals are just as good as the prescription ones.