At the end of week 4 of pregnancy, you'll be expecting your period (or hoping not to get it). Taking a home pregnancy test at the end of this week might possibly confirm that you are a soon to be mom.
You're not "showing" yet and you haven't gained weight at this point, since your baby is so tiny. Your hormones are undergoing major changes, so mood swings are completely normal during this time and throughout your pregnancy.
By the end of this week of pregnancy, the fertilized egg is embedded more deeply in the lining of your uterus and the amniotic cavity, which will be filled with amniotic fluid, is starting to form.
The early version of the placenta is forming and the very beginning of the connecting stalk- which will become the umbilical cord- has appeared. Until your placenta is fully functioning, the yolk sac, now present, will feed your baby. Different germ layers are developing and the vascular networks that contain maternal blood are being established.
