There is no such thing as expired food. The date is a guideline, and is set conservatively to protect the store. 4 days is nothing. And you'd smell it if the egg was bad.
Try and learn that food doesn't suddenly go bad on a particular day. Use your senses to find that out. How else did we manage before there were printed dates on anything? Bad eggs STINK so you'd know! Another good test of an egg is to put it in a bowl of water. If it sinks, it's fresh. The air pocket in the egg gets bigger with age so if it starts to tip up towards floating, it's less fresh. If it actually floats, it's stale.
And food poisoning is caused by bacteria, which do not spontaneously generate once an egg is over a certain age. The egg actually has to be infected to cause that,