from my personal experience, I stopped vomitting when the bb is 4 months old. I usually vomit when I brush my teeth or I feel hungry. I feel worse if I ate sweet thing. Hope this help.
sigh....actually I had stopped my vomit since 10 weeks, however, I'm now 12 weeks and the vomit start again yesterday and made me can't go to work, very horrible feeling....so, I may have one more month to go......( but when thinking of my bb, it's ok la), haha