Becoming pregnant and adding a new member to the family something that most women react to with joy, but that doesn't mean that pregnancy itself is easy or comfortable for all women. During the first trimester of pregnancy, it is not uncommon for women to experience nausea and vomiting, which is commonly referred to as morning sickness. Despite its name, nausea and vomiting can occur at any time of day, and some women can feel unwell all day long during their first trimester.