Most women who become pregnant are very interested in what is to occur in their lives.  They want to know the pregnancy stages that will occur during the time that they are pregnant.  There are three stages of pregnancy and they are known as trimesters.  You will experience three of these throughout the pregnancy and many pregnant, women think the most uncomfortable of the trimesters are the first and third ones. So, that is something to think about while you are pregnant and aid you in knowing what is to come.