I think i might have eaten some dodgy cheese and onion pie this morning and i've had chalky stool since, i've been to the toilet twice since and the colour hasn't changed. is it food poisoning or should i be concerned and seek medical help?

Classic acute food poisoning by staph toxin causes almost immediate nausea& vomiting followed by explosive diarrhea within a few hours. Other causes of food poisoning are less explosive. Your loose,chalky BMs may be more of an intolerance than actual food poisoning. I think you can sit tight for now. Eat only soft,bland food until symptoms resolve. BMs should normalize within a couple of days.