Most of my first symptoms started leaving at around 10 weeks, and they were completely gone by the 11th week.
What I have had to remind myself, though, is that the symptoms are not gone. Just nausea and fatigue are gone. I think because those were the main and most prominent symptoms, it just felt like my symptoms were gone when they left.
But I am still sensitive to smells, I have some dizziness upon standing, I am still having crazy dreams, boobs are still sore. I also still have plenty of food cravings and aversions.