Question about warranty.

I got the letter from XBox saying my warranty was almost up and it had the prices of what it would cost per year for a new warrany.

Well, I was going to get a 2 year warranty. So, I stuck the paper in with my bills to pay. I went to do it today and it was past the date when I could send it in. Does anyone think I could still send it in? Or should I call the 1-800 number and ask before I do? Nothing is wrong with my Xbox. Work's great. I just want a warranty if something happens.

Thanks! :)

I'd call to be sure