Hi, I'm new here and haven't yet earned my BP.net wings, but I'll share this with you. A healthy snake can go months without eating - and some do on their own accord. And three weeks between meals is not a problem for a healthy snake. Some snakes do it for brumation, sometimes they do it because they want to shed first (or other reasons), some do it "just because." Adult snakes can handle and might be best at feeding every 3-6 weeks, another similar, non-professional link, another link (just trying to help). Don't stress too much, he's probably fine and he will be more likely to eat if you wait the two weeks to try another feeding.