Your growing baby
Your baby and the yolk sac are about the size of an M&M's candy. A month after conception, your embryo looks something like a newt or a tadpole, and it has gills like a fish! Right now, the embryo of your future baby looks much like the embryo of any other animal—a bird, rabbit, or monkey. It has two tiny cups of pigment on the side of its head that will develop into eyes. Tiny buds that will form the lungs have appeared. The neural tube has closed. On end is flattening and expanding to become the brain, and the other end will become the spine. It's already 10,000 times larger than the fertilized egg. The embryo doesn't have gender characteristics yet, but has little dots where the nipples will be, whether it's a boy or a girl. The heart, a tiny U-shaped tube, will start beating between days twenty-one and twenty-four and is circulating the embryo's own blood. It has a small mouth and lips and fingernails are forming.
Your changing body
Your production of pregnancy hormones (hCG) continues to increase, making you susceptible to nausea and fatigue. Your blood pressure is lower than it was before you were pregnant, which can make you lightheaded and dizzy. The extra progesterone and other hormones may be making you feel tired, achy, nauseous, and cranky, or you may not be feeling much different than normal. There's no need to stop exercising or curtail your activities, unless you want to. In fact, keeping active will help your body be more able to cope with the stress of carrying around the extra weight you'll be gaining.