Oh dear yeah your body defo rejected it, Its not even like you ate something bad it was one of your packs read on here many people have made crisps with their packs mmmm cant think why, maybe speak to your CDC about it? I am only in week 4 so by no means a pro on the diet, but it could of been a one off time it happened you had a bad headache before right? Do you feel ok now or still bad?