Dark Stool?

Does anyone ever get dark stool? I wasn't really concerned yesterday because I ate half of a crumbl oreo cookie yesterday (I had a weak moment 😭) but shouldn't it be out of my system by now? My stool was black yesterday and I wasn't worried, but It's been almost/somewhat black twice today & now I'm a little spooked. Should I call my transplant center or give it another day? I'd hate to freak over something that turned out to be nothing(I'm also trying to avoid an incoming IV).

Update: I decided to be an adult & called my doctor. Thanks yall!