Weird reactions

I had 2 reactions to pasta a few years ago, but I had a bag of gluten candy without realizing last year and was fine and yesterday had one piece of candy I shouldn’t have and after 30 hours no reaction. I’m very confused because I don’t think I’m doing much wrong? My gastro said I’m fine and my levels were good, I was slightly iron deficient but it’s probably because I don’t eat meat too often, so I’ve been doing that more. Should I be worried it could happen later on?