It's different for everyone. With my first I had fatigue, nausea, and food aversions starting around 7w.
With my twins it was from exactly 5w until exaclty 6w.
With this pg I had fatigue start around 4w, and since then it's come and gone. I had 2 days of nausea, and a week or two of horrible aversions and hardly ate anything (I lost 5 pounds in less than a week because I couldn't eat anything).
Don't worry about the symptoms, some people's body are able to handle the hormones better than others (no idea if that's grammatically correct, sounds strange but I can't think of what would make it better - any English teachers?). You'll probably get symptoms later and kick yourself for being sad not having them right now.