IIRC, you should recieve something in the post soon - some MBP owners have had the same thing, and I think, again, IIRC, that they reported docs arrived in the post some weeks later. You can, however, go to apple.com/support and type in your serial number on the page, and it will tell you how long you have left (hence telling you if your extra applecare is activated).
If you do not recieve a package (which you should), then call Apple and ask them to send it to you - after all, you HAVE paid for it...