Is she pregnant or not?

Question
I live in the country, so there's a large population of un-altered feral/stray cats around here. One of these strays suddenly decided she wasn't going to be timid anymore and has allowed herself to be petted and even picked up when before she would run away if you even looked at her. I thought nothing of it, thinking I'd simply won her over with food. Soon after she started acting this way, I couldn't get her off my porch, she claimed a pile of blankets as her own and took to sleeping there. I had to take my poor dogs outside on leashes so they wouldn't chase her! She soon began gorging herself on food, and being downright vicious to our resident tom, (she's much larger than him) chasing him off when he gets close and denying him access to the porch and food.

Due to her rounding belly and sudden personality change, I assumed her pregnant and brought her inside, (still haven't taught her to use the litter box yet...). She's been inside for nearly two weeks now, and is now VERY "fat", looking like she's ready to burst.

Now, I know that pinkened and larger nipples are one of the easiest ways to tell that a cat is pregnant, but the problem is she's fluffy, so it's hard to find them, not to mention she bites the crap out of you if you touch her stomach or tail area. I've only ever been able to locate one nipple out of her supposed eight, and it didn't seem overly pink or large to me.

My question is, can she be pregnant even without the change in size or color of her nipples (this could be one of her many pregnancies)? Or is she just fat and moody (she attacks you if you pet her and then try and leave...) and I can kick her out of my house after taking her to the spay-clinic?~ If she IS pregnant, should I be concerned that she isn't going to be able to provide milk for her kittens and stock up on milk replacer?

Answer
Firstly have you considered a bad infestation of worms? Considering her history this could be a real cause for concern and needs to be dealt with anyway due to your dogs being in the house as I'm sure you wouldn't want them to catch worms.

If as  you say, she is very fat now, I would have expected her nipples to all be enlarged and although you say she doesn't like you to touch her, they should still be able to be felt through her fur.  

Even if she is pregnant, I would strong recommend that she is wormed as the worms will debilitate her greatly and will weaken her kittens.  It may be that once she is wormed that her stomach will go down.  If she is pregnant and if she is very fat, then you should shortly see the kittens moving which will clinch the matter.

Most cats will produce milk for their young but it wouldn't hurt to have some milk powder ready to hand - its certainly something I would not be without. I would however wait until you can see kittens moving before you stock up as it could still just be a case of worms.

Marcia