When talking about the size of a developing baby, most healthcare providers will discuss the size in terms of `crown-to-rump` length. Crown-to-rump length simply means the distance from the top of the baby's head to its buttocks. Because the baby's legs are usually bent or tucked inwards, crown-to-heel length is hard to determine. By the sixth week of pregnancy, your developing baby is 2 to 4 mm long. You may have even gained a few pounds at this point. However, if you have been nauseated or not eating well you might have lost weight.
You have actually been pregnant for an entire month now! More than likely, you have noticed some changes within your body and you might also notice that your clothes are fitting slightly tighter around the waist. Some women also gain pregnancy weight in their legs, face and breasts. It is not uncommon to experience heartburn or constipation at this time either. Symptoms are usually not severe at this time. If you were to have a pelvic exam at this point of your pregnancy, your doctor would be able to feel your uterus and would notice some changes in its size. Although you will not be able to hear your baby's heartbeat with a Doppler yet, you might be able to see it beating if you have an ultrasound now.