Week six is the time when the fetal heart beat is first visible on an ultrasound. The baby is about ¼ inch in week six. It is growing rapidly. Ultrasound images at week six will show a small black circle (the gestational sac), a small white line (the fetal pole), and a little flicker in the white line (the fetal heart beat).
The baby is developing rapidly, the heart is forming, and the face is also beginning to form. The baby is taking shape and starting to look like a little baby at this point. On ultrasound it really just looks like a white line but that is only because the technology cannot magnify the image large enough to see all the detail.
The pregnancy hormone, HCG, is rising rapidly during week six. HCG is the hormone that is responsible for pregnancy symptoms. The typical symptoms are breast swelling and tenderness, fatigue, and nausea and vomiting. Most women do not have all of the symptoms and some have none. Do not be alarmed if you feel well, be happy. Lack of pregnancy symptoms is not a sign of miscarriage even if they where present and then disappear.
If you have not already done so, this is a good time to call for your first prenatal doctor’s visit. At your first prenatal appointment you will likely have a physical exam and blood work ordered. You may be scheduled for an ultrasound as well. If there is any discrepancy between the weeks estimated from your last period and your exam, An ultrasound can help define the due date. Ultrasounds may also be ordered for a history of miscarriage in the past or if there is any bleeding. Neither of these issue are particularly dangerous but an ultrasound will help give you piece of mind that everything is alright.