Mice pregnant, males, what?

Question
I brought two female mice a month ago from a big petshop and a week later on I brought one male to breed them with. After another week or two went by both females looked like they swallowed a ball. They were eating a lot more and hid from me everytime I opened the cage door. Although after another week, possibly two, my females got rounder instead of pear shaped. The male is now smaller than both of them and they have formed two lumps around their anus like testicles. Im not sure if they are pregnant anymore, is it possible that my mice lost the babies?? or that they could be males??

Answer
Dear Mackenzie,

If they have identical conditions then it is probably correct that they are males.  Some males develop faster than others.  

Check out this very useful page to help sex mice of any age:

http://www.thefunmouse.com/info/sexing.cfm

If they are males, they might fight and need separate cages as they grow older.  My rule is if they draw blood they need to be separated.

squeaks n giggles,

Natasha