Is is normal that morning sickness peaks at 8 weeks and star

I am entering my ninth week of pregnancy. I'm worried because I started to have morning sickness at the beginnning of the seventh week, it came and went but was quite unpleasant (I did not vomit but felt I was on the verge many times), and now I feel much better. I am still slightly queasy much of the time, and I have all my other pregnancy symptoms: sore breasts, gas, fatigue, most odors repulse me. I had an ultrasound last week and heard the heartbeat. But....isn't it too soon for my morning sickness to be getting better?? Is is normal to have morning sickness that peaks at 8 weeks and starts to go away at 9 weeks?