Mine has been VERY mild and not constant, but in week 5 I would notice a gagging sensation in my throat that made me nauseous for a minute then went away. Then in week 6, one night I just woke up really nauseous and its come and gone like that ever since. It happens if I'm hungry, or if I'm full, just comes on randomly. I have yet to throw up though, although came pretty close this morning brushing my teeth. That was another thing I noticed...around week 6, brushing my teeth became a real chore.