papillion purebred?

Question
I got a "purebred" papillion puppy for my mother in law last christmas.  He looks like a typical papillion except for the fact that he isn't a year old yet and weighs 15 pounds.  We are not looking at trying to bred him or anything as he was fixed about 3 months ago.  My mother in law wanted a papillion because she flys alot and wanted to be able to take him along as a carry on when she flys. I thought that this dog would get to be no more than 8 pounds. She loves her doggy but it would be nice to find out if he isn't a purebred.  Thanks for your help.

V/R
Kim

Answer
Well some dogs are a lot bigger than what the standard calls for so size alone does not mean the dog is not purebred,as I have known of a Pomeranian that weighted 18 pounds,ten pounds over sized. Just as some can be runts some can be bigger as well. If you can send me a pic I could tell a bit more based on that