Brie Cheese and expiration date
Cheese is a durable food, and the date printed on it is more of a best-by date than an expiration date. While brie is rather soft (which is normally a problem because soft cheeses are more welcoming to bacteria), its colonisation by noble mold fills the ecological niche which would be otherwise claimed by pathogens. So, especially if you kept it in the fridge, eating it a few days or weeks after the date printed should not be a problem food safety wise. 

As with most mold cheeses, you may find that it has overripened. Overripened mold cheese will have a gooey to liquid core and a somewhat funky smell. It is still safe to eat, but you must decide if the taste is still good enough for you.