In week three of pregnancy we see what is actually the first week of the baby's life after conception. The baby is very tiny at this point, a cluster of cells that is about the size of the head of a pin. However, these cells are growing and multiplying at a very fast pace.
The developing cells are called a zygote before they implant in the uterus. Failure of the ball of cells to move into the uterus before implantation will result in an ectopic or extrauterine pregnancy. This can be a serious and life threatening emergency. For most women though, the baby implants into the uterine lining about six or seven days after the egg is fertilized.
When the fertilized egg implants itself in the uterus it finds a thickening, nutrient-rich lining waiting for it there. Hormone production in the woman's body keeps the lining of the uterus growing so the baby finds a hospitable environment when it enters the uterine cavity.
The cells on the outside of the ball of cells will burrow into the lining of the uterus, later becoming the placenta, umbilical cord and amniotic sac. With this implantation the baby is now considered an "embryo" in medical terminology. This embryonic stage, lasting from 3 to 10 weeks, is a time when the baby is highly susceptible to hazardous substances, toxins or medications you are exposed to.
Sometimes this burrowing action causes light bleeding or spotting. Since this often occurs around the time of an expected period, and it is still too soon for other signs of pregnancy, a woman may think her period is starting. This light spotting is fairly common and as many as 20% of mothers experience some form of bleeding during their pregnancies.
By the end of the third week your baby is likely implanted safely and securely into the wall of the uterus and will soon begin the transition from taking nourishment from the yoke of the egg, to receiving nourishment from your body. In fact, if you have not yet begun eating a healthy diet conducive to a healthy pregnancy, now is the time to begin!
Did you enjoy this article? It is part of the Pregnancy - Week by Week Through the First Trimester ebook available today!
Resources:
The Pregnancy Book: Month-by-Month by Dr. Sears
Your Pregnancy Week by Week by Lesley Regan
The Complete Book of Pregnancy and Childbirth by Sheila Kitzinger
