Most commercial pasteurized fluid milk is probably not pasteurized before 3 days (it can spend 48 hours at the farm, and then is trucked to a plant, where is may even be passed onto a second plant first). Then however long before making it to stores, being put out on the shelf, brought home, and then opened and drunk. So two weeks doesn't sound high either. Not to say that a fresher milk won't taste better or be more nutritious though!