Two years ago I took a friend on a flight to get some food. He got a little airsick on the descent when it got a bit bumpy. We ate a huge, greasy lunch, much to my regret because about half way back to our home airport, he needed an airsick bag, and odor propagates through a 172 cabin very quickly...
Anyway, happened to me in the beginning, but haven't had nausea since about 5 flight hours. Had some students go through the same thing. Nothin to worry about.
