One of the first signs of pregnancy may be a nauseous feeling. When your hormones are changing during pregnancy sometimes the sight or smell of certain foods can cause you to fell nauseated. Although it is referred to as morning sickness it can occur at any time of the day or the night. Morning sickness usually happens during the second through the sixth week of the pregnancy but can continue even longer before it eventually passes. Morning sickness is not harmful to you or your baby unless you experience excessive weight loss. If you have persistent vomiting you should see your care provider.