There are three distinct stages of pregnancy, called trimesters, each about 13 weeks. The stage of pregnancy, or trimester, is important to your baby's growth and might be uncomfortable for you. As your body adjusts to the raging hormones of a new pregnancy, you might experience morning sickness and moodiness. Your breasts will swell and you will miss your period. Your baby will grow from a small cluster of cells to an embryo with the beginnings of eyes, ears, fingers and toes. The baby will be able to move his arms and legs. At the end of the first trimester, you may notice that you are "showing" and your doctor may be able to tell you what sex the baby is.

During the second trimester, your belly will grow as the baby does, and you will begin to feel the baby move. You may experience headaches, dizziness and backaches from the changes happening to your body. Luckily, morning sickness has disappeared, but you may begin to retain water. Your baby's bones are developing and he is covered with a fine layer of hair called lanugo. As your belly expands, you continue to gain weight. Despite this, the second trimester is the time most pregnant women enjoy the most.

The baby's growth slows by the end of the third trimester. Vital organs are developed and fat begins to develop under the baby's skin. During the last weeks of the third trimester, the baby begins to descend into the birth canal. You will have gained 25-35 pounds (ideally) and you may experience some fatigue and numbness in the pelvic area. Urination is more frequent and your breasts may start to feel heavy and leak. Of course, the third trimester ends with the birth of your baby!