Nausea during pregnancy occurs in 70% of women during the first trimester. Also known as morning sickness, first trimester nausea makes you feel sick to the stomach and is accompanied by vomiting in the first few pregnant months. It is referred to as morning sickness so people expect nausea in the morning, however, this feeling of nauseousness and vomiting can occur at any point of the day and can even last all day.
Morning sickness is an early sign of pregnancy and can start as early as when implantation happens.