Nausea and vomiting are common in pregnancy, especially in the first trimester. Some pregnant women experience excessive nausea and vomiting. This condition is known as 'hyperemesis gravidarum' and often needs hospital treatment. ... It's much worse than morning sickness.

To help prevent and treat nausea during pregnancy, try: Home or natural remedies
Avoiding foods and smells that trigger your nausea. Keeping soda crackers by your bed and eating a couple before getting up. Allow some time for digestion, and rise slowly once you are ready. Eating smaller meals more frequently throughout the day instead of three big meals. Drinking less water/fluids with your meals, and instead, drink them between meals. Eating drier, plain foods such as white rice, dry toast, or a plain baked potato instead of richer, creamier foods.
Sucking on hard candy. Keeping rooms well ventilated or having a fan close by for easier breathing. If neither of these is possible, take time to go outside to get some fresh air.
Getting plenty of rest; Listen to your body when you are feeling fatigued, and try lying down. Sniffing ginger or lemons, or drinking ginger ale or lemonade, which can help ease the feeling of nausea. Talking with your healthcare provider about the prenatal vitamins you are taking; having too much iron may cause nausea, and switching to a different vitamin could help. Asking your healthcare provider about taking a vitamin B-6 supplement, which has proven to help reduce nausea and vomiting.