I have a bitch here who is one week post breeding for her second litter. If I didn't know better I'd be sure she was pregnant. Seems like over night she has the tufts of hair on her flanks standing out like she did with her first litter and just like every other bitch I've had pregnant.

Isn't it too early to notice any changes??? She is sleeping in the same positions as always and her fur was not like this yesterday...

I think experienced breeders really know their bitches and can tell (not 100%) but can tell a little if the bitch is preggers or not... I could always tell on my girls much earlier than they say you're suppose to be able to tell :) I wasn't 100% sure but I still had something telling hunch me that she was preggers :)
Good luck to you and your girl!