You've just seen the + sign on the test - Your Pregnant!! Congratulations! It is an amazing journey you are about to begin. You'll go through many changes, both inside and out. And, so will your growing baby. Before you even knew you were pregnant, your body and baby were already working very hard. During the first 3 weeks from conception to the time the pregnancy hormone HCG (human chorionic gonadotropin) can be detected by a pregnancy test, your baby has grown from a newly fertilized egg, to what scientists call a "blastocyst". This "blastocyst" is essentially a ball of very rapidly multiplying cells. As these cells multiply, a water tight sac begins to form around it. This will become the amniotic sac. Also during this time, the part of the "blastocyst" that will become the placenta begins producing HCG. The production of HCG tells your body to stop releasing eggs from your ovaries, to increase the production of estrogen and progesterone, and to hold onto that uterine lining.
By the 4th week of pregnancy the placenta will be formed. The placenta will work very hard for your baby throughout your entire pregnancy. The placenta will bring oxygen and needed nutrients to your baby, while eliminating the waste she creates. The placenta will also prevent your blood cells from mixing with your baby's as well as making sure your immune system doesn't reject your baby as a foreign invader. And, as your pregnancy progresses, the placenta will do even more!
As your pregnancy progresses, your baby will continue to develop at an astounding rate. This time is very critical developmentally, as the basics for all the systems of her body are formed during this initial period. By the time you are 8 wks along, your baby is about the size of a kidney bean! She will have webbed fingers and toes poking out from her hands and feet. All her other essential body parts, such as eyes, ears, nose etc are formed, though they will change dramatically from the way they look now, to how they look when you will finally see your baby 7 months from now. Also during this time, breathing tubes will begin extending out toward her developing lungs. And, in her brain, the beginnings of neural pathways are forming.
On the outside, you will look no different during these first 3 months, though you may feel very different. You may feel increasingly tired, nauseous, and, honestly, just horrible! This is an amazing time in your life, but it really is OK to embrace feeling like crap! For most women, all of this will subside and you will begin to feel much better by the 2nd trimester. But, for right now, do as much as you can to listen to your body, and take care of yourself. It takes a lot of hard work to grow a baby!
By 11 wks, or so, the baby enters what is called "the fetal period". With much of the critical period of her development behind her, the tissues and organs of her new little body begin to quickly grow and mature. Your baby's kidneys, brain and liver are beginning to function. She can move her arms and legs and the webbing that was there on her fingers and toes just 2 weeks ago is gone, and she actually has teeny, tiny, little finger and toe nails!
By the time you are 13 wks along, and ready to enter your 2nd trimester, your baby will look very, very different than when she began forming just a short 13 wks ago! She will be about 3 in long, and if you do indeed have a girl, she will already have more than 2 million eggs in her ovaries! Your baby's skin is clear, and all of her veins and organs are still visible through this "skin". And, although you don't feel it, your baby is moving all about inside the wonderful world of your womb. In fact, if you poke on your abdomen, your baby will squirm around in response!
