Mouse Pregnant?

Question
I've had two female mice for 10 days now.
i bought them from a pet shop and i was told they're 10 weeks old...
i noticed when i put them in their tank that one was larger than the other.
recently she's been making noises like... snuffly squeek
i bought her downstairs and showed my mum
she said that she looks pregnant (the shape of her body)
i looked at some pictures on google and theres one that looks EXACTLY like her body shape.(http://oslovet.veths.no/teaching/mouse/techniques/rederive/1a.jpg)
shes playing on her wheel lots
and shes ripping up lots of newspaper and dropping it in her bed..
i was just wondering if you could give me your thoughts?
and also if she is pregnant, should i seperate her from my other mouse?
thanks.

Answer
Dear Charlotte,

Your mouse is certainly pregnant.  Girl mice are sexually mature at 4 1/2 weeks!  It is an irresponsible pet store that keeps boys and girls in the same cage after that age, unless they warn customers that the girls might be pregnant.  

Don't take the other mouse out.  She will be of great help to the mother mouse.  She will sit on the nest so the mom can run in the wheel and eat, etc.  

I've answered a lot of questions about mouse pregnancy and raising babies, so do some searches in my archives or on the site (use the search words Mouse Mice Natasha and then Pregnant or Babies etc.).

Best of luck and have fun with the babies!

squeaks n giggles,

Natasha