Health concern or wrong sex?!

[BeautysFamily]

Hi all
I'm a (very obvious) newbie here...we purchased a female (or so we were told) syrian hamster almost two weeks ago and over the last few days I have noticed a "swelling" around her bum. Of course the first thing I done was Google this and I am now wondering if she is in fact a he?! Or indeed whether this is something I should be getting checked by a vet? I apologise for the quality of these pictures, unfortunately our baby still doesn't like to be handled, despite our best efforts at taming - although again through googling recent behaviour I have learned that the pet shop have actually sold us a cage which is far too small for her (or him) and so I am eagerly awaiting delivery of a new home for her tomorrow and hope that this may help her settle in better.
Thanks in advance for any input anyone can offer!!

[souffle]

Yes you have a male hamster there. Sometimes it's not that obvious when they are babies or when scared they can retract the testicles but pet shops are notorious for getting the sex wrong.

[BeautysFamily]

Thanks so much for replying and confirming