It all begins with an egg and a sperm, as you all know! At the very beginning of pregnancy, these two come together. After that, the fertilized egg travels down to the uterus, where it will commence implantation. This development takes place in week four of pregnancy (which is, in fact, two weeks after fertilization, but four weeks after your last menstrual period that is how your due date is calculated!). The placenta, the organ that will nourish your baby until birth, is also starting to form. A week later, the embryonic stage will commence. This is significant because it is the time when the baby's heart, brain, spinal cord and other essential organs are beginning to form. The tiny heart will already start beating and pump blood around the tiny body with the help of a still primitive circulatory system.
Halfway through the first trimester, your future baby will already have basic facial features. Isn't that amazing? By week seven, the embryo will have a separate head, and arms and legs also start to develop, though they are nothing but minuscule buds at this point. When you reach week eight of pregnancy, and are likely to be in the full swing of morning sickness, your baby will already start making movements. Of course, you will not be able to feel it yet. Two weeks before the end of the first trimester, your baby will have a neck and eyelids, and it can open and close its eyes! A week later, genitals will form, and your embryo becomes a fetus! Congratulations, the first twelve weeks of your pregnancy are now over!