What happens if I give my baby milk that is past it's "should be used by" timeframe?

ok...nobody judge me...I am just asking!! :) So for my 15hr flight to the states yesterday I took a bunch of milk with me in a cooler. Well, my son (who is 7wks old) didn't eat nearly as much as I thought he would so now I've got a bunch left over still. I know they say you need to used un-thawed milk and milk that was ...stored in an insulated cooler within 24 hrs but I hate to throw all that milk away. I've got about 500ml left from the trip which for me equals about 5 feedings. So, what would happen if I give it to my son? Would he get sick? I don't want that to happen. Please let me know if you know what to do!! Thanks!See More