Your body: Even you may not know you are pregnant, your baby is starting to grow and develop. Over the past week, the fertilized egg has divided into hundreds of cells and is now called a blastocyst. The blastocyst is hollow and filled with fluid and is not yet visible. Around week three (somewhere between days 4 and 7) the blast cyst implants itself in the endometrium, which is the lining of the uterus. This is very important as it will provide the nutrients the egg will need to develop. Eventually, the implantation site will develop into the placenta.
Your body will now let you know that you are pregnant because the blastocyst will begin to secrete hormones to prevent your body from releasing tissue in your uterus- you may notice that you have missed your period.
