Okay, so, long story ...
Basically, there was a bunch of cats that always hung out at my boyfriend's stepdad's work (he works at the local mall). One of them, a very sweet girl, had a very bad cut one day. Her side was literally torn open and muscle was showing

We thought it might have been the resident tom, or it might have been some cruel kids we heard about who claimed to have been throwing a cat up to see if it would land on its feet

But that's not the point of this story.
Anyway, since her cut was so bad, we took her home for a little while to let it heal since we didn't want it to get infected, and we didn't want the tom to kill her if it was because of him. So she's been living in our garage for a little over a month.
She's suddenly gotten fat. Very fat. And she's a small cat.
Now mind you, my boyfriend's stepdad has been overindulging her since, being a stray, she ate like she'd never seen food the first few days. But she's more than doubled in her weight since she arrived.
She's probably anywhere from six to eight months old by our best calculations.
We've tried to feel for kittens, but my boyfriend's mom said she couldn't feel anything but belly. The cat, who is normally VERY affectionate, didn't even let me touch her belly. I don't even know if you'd be able to feel them this soon.
Does anyone here know any ways to tell if a cat is pregnant? Or are we just going to have to see if one day in a month or so, we go out to the garage in the morning to see more than one cat greeting us?
She's going to be going to the vet (since it's looking like we're going to be keeping her), but I'd just like to know if there's any way we can know for sure before then. She won't be going for at least three weeks since she'll have to be spayed before we can bring her inside and they're all booked up for at least that long.
Any help would be greatly appreciated. Thanks!
BTW, her side has healed up very nicely with no complications, in case any of you were wondering
