It basically means your baby is running a construction site inside you! Nausea is just a nice word for morning sickness, which actually lasts all day. Hang in there, ginger candies might help a bit.
Honestly, it is just morning sickness and it's because of all the pregnancy hormones. I had it so bad till week 14, now in my second trimester it is better. Did anyone else have it last even after the first trimester?
My doctor explained that rising hormone levels, especially estrogen and hCG, cause this nausea. She told me it's actually a sign of a strong pregnancy, but warned me to report if it leads to rapid weight loss.
It's just your body adjusting to the beta-hCG hormone. But please, if you are vomiting so much that you can't even keep water down, go to your doctor. I had severe dehydration because of this and had to get IV fluids.
Nausea is simply that urge to vomit, very normal in early pregnancy. Don't worry, your body is just working hard. Eat small meals and keep dry biscuits on your bedside table.