Popcorn and corn are gluten free but you could have a corn intolerance or there could be added gluten to the products you ate. I know I have to be careful about chips because many of them have gluten or are produced in plants where they could get contaminated. I don't know about microwave popcorn and what additives it might have because we do ours on the stovetop with coconut oil. So you'll need to first look at the ingredients and see if you got contaminated with gluten. If that's not the case then keep a food journal or at least pay attention to how you feel after eating corn products. I probably have a corn intolerance too but I'm still in denial over it because I LOVE popcorn.

Lots of people with gluten intolerance/Celia's also have issues with corn, though corn is gluten free. Neither my son or I can handle corn products to go along with gluten.