touching the bump

I know it's a urge people have when seeing a pregnant woman to touch their stomach but am I wrong for telling people not to? I just don't feel safe when certain people do it like some girl came up to me and was like are you really pregnant so...if I do this what would you do i was in school at the time just graduated but I just dont allow certain people to plus my nana said you're not supposed to anyways she's the whole spiritual person and says not everyone is good but am I being an asshole