Are My Guppies Pregnant?

[guppyhelp]

I just purchased 1 male and 2 female guppies from the pet shop. They said my guppies aren't pregnant but to me it looks like they are! Can someone tell? And if so what stage are they at? THANKYOU
 
This is the youtube video of the guppies.. http/www.youtube.com/watch?v=1rpznKTOiKo
 
seriously all responses are appreciated! I was driving myself crazy today, 10 pet stores and EVERY female guppy pregnant. Even the ones I thought weren't ended up being  

 

[Kellene]

They look pregnant to me! The little dark spot by their anal fin (the fin closest to their tail) is called a gravid spot. If the spot is dark like that, then the guppies are pregnant. Get ready for lots and lots of fry

 

[Fizzy77]

If they aren't they will be soon, if you don't want your guppies to breed you should keep only males (cuts out the worry of buying pregnant females!!) They do look pregnant

 

[fishmad135]

As the others have said they do look pregnant as they have a gravid spot, however they aren't that plump, let alone 'squared off' so they will be early stages in there development. 
Sometimes the dark spot on by the guppies anal fin is just a marking so the guppies may not be pregnant.. but not likely!