
I think it would depend what date the breeder puts down on the forms. If it was done before you took your puppy, (mine was done at 7 weeks of age but she was 8 weeks before I got her, this was because some of them were going at 7 1/2 weeks) so she was covered before I picked her up. However my first puppy wasn't covered until I registered a change of ownership myself, which took ages.
I might be wrong though, my memory isn't what it used to be :)