Yes, this happened to me. I think my MS peaked around about 12-13 weeks or so, and I was still sick up to 6.5 months- but don't worry, that's pretty unusual. For most people, it will fade by 15-20 weeks, even though it feels like it won't.

As you probably know, it all about your HGC levels- they are increasings heaps and it can make you awfully sick. Its so horrible, isn't it? The only thing that consoled me was the whole "m/s = healthy pregnancy" thing.

Best of luck and I hope it lets up for you very soon!