This will most likely be a silly question but I figured instead of consulting other forums that I've been looking at, I'd come here and ask you guys.

I read that a way to tell that your mouse is pregnant is if you place a piece of toilet paper in their habitat and they take it to their hide then it could mean they're pregnant (nesting). So, I tried that because my mouse has been looking a little fat and she came from Petco so it's not at all impossible that she is. Well, the next morning that I woke up the piece of toilet paper was inside her hide and she has been moving around like a nut all day and night. I constantly hear her rustling and she is bending some newspaper to make a sort of tee-pee like thing in the corner of the cage. Also, in her hide, she's been taking little crumpled pieces of paper and putting them into her hide.

So, the mystery I'm looking to solve is: Is my mouse pregnant?