Since coming out of the store, or the chicken? ;-)

Store.

The one time I had a nasty reaction to a cold egg it only took 5 minutes.

Wiki says: "The delay between consumption of a contaminated food and appearance of the first symptoms of illness is called the incubation period. This ranges from hours to days depending on the agent, and on how much was consumed. If symptoms occur within 1–6 hours after eating the food, it suggests that it is caused by a bacterial toxin or a chemical rather than live bacteria."