The ball of cells has implanted in the uterine lining and is now an embryo with an amniotic sac and yolk sac forming around it. The three germ layers that will become skin, organs, muscles, and bones are laid down. The neural tube, which becomes the brain and spinal cord, is just starting to form.
A pregnancy test may just be turning positive as hCG rises. You might notice light implantation spotting, tender breasts, mild cramping, or fatigue — or nothing at all.
This week's tip: Start or continue a daily prenatal vitamin with at least 400 mcg of folic acid to support neural tube development.