Sorry to be the bearer of bad news... but for me morning sickness got worse at 12 weeks and stayed terrible (i.e. unable to work, on special medications) till 16 weeks and was then pretty bad until 26 weeks.

They don't really know what causes morning sickness - some people thinks it's linked to hormone levels. If you are vomitting several times a day, consider seeing your Dr - I was starting to get dehydrated and had no energy. I also tried accupuncture - it didn't really work for me, but you get to the point where anything is worth having a go!