Maybe I will ask back, why do you feel that I'm preggy? Hm, if they talk about some behaviour changes or feel my food in take increase. Maybe can answer, dunno.. but just have craving for food..
As you don't want to deny in the first place. To me, as I have bloated tummy case before, I may say that tummy not feeling well, need to take more meals and small portion to ease the uncomfortable.