At 12 weeks, your baby is roughly the size of a plum.
Your baby’s facial features are continuing to distinguish. In addition, your baby’s fingers and toes are also becoming longer and more distinctly separated from each other. This is largely because more muscles are forming, and bones are solidifying and growing (before it was mostly cartilage). This development also allows your baby to start moving, and even coordinate some of that movement. Some women may be able to detect very small fetal movements around week 12, but don't worry if you don’t most women don’t feel their baby move until about week 20.
The placenta that filters blood and nutrients between you and your baby is formed and is now the main source of those things for your baby. Around it, and your baby, is the amniotic sac, which contains amniotic fluid (the “water” when someone talks about their water breaking and going into labor). Amniotic fluid is increasing in quantity to create a cushion around your baby and provide a protective environment.
