It is common for pregnant women to experience nausea and vomiting, commonly known as morning sickness, during the first trimester. However, some women may continue to experience these symptoms into their second trimester. If you are now experiencing vomiting in your fourth month of pregnancy after only having nausea before, it is important to consult with your healthcare provider. While occasional vomiting can be normal during pregnancy, persistent or severe vomiting could be a sign of a condition called hyperemesis gravidarum. This condition can lead to dehydration and weight loss, so it's crucial to seek medical advice if you are concerned about your symptoms. Your healthcare provider will be able to evaluate your specific situation and provide appropriate guidance and treatment options.