If you've just found out you're pregnant, you might want to start by reading the previous sections. The embryo growing inside you is very small. At this point, it is only a group of cells, but one that is multiplying and growing very rapidly. The embryo is the size of the head of a pin and would be visible to the naked eye if you could see it. In this third week of pregnancy, you won't notice any changes.
Few women know they have conceived.
Remember, you haven't even missed a period yet. A great deal is happening, even though your pregnancy is in its very earliest stage. Ovaries lie free in your pelvis or peritoneal cavity. They are close to the uterus and Fallopian tube. The release site on the ovary is called the stigma.