Signs of pregnancy?

Hello!

A couple of days ago I took in a female cat to foster until a local cat rescue has room to take her in (although I might just keep her, she's growing on me!   ). The lady that had her said she showed up with kittens about 2 months ago, and found homes for all of them but not her, and since it's so cold she didn't want her to freeze.

The signs I am worried about are:

-swollen mammary glands/mammary pad

-constant purring

-eating a lot

-slightly round abdomen

-has been outside this entire time with plenty of stray toms

As odd as it might sound the mammary glands are what tipped me off the most, because in my necropsy class I had to dissect a nursing queen and her mammary glands/pad was very different, and my prof said they are only like that when the queen is nursing or getting ready to nurse. Could they simply be like that because of her last litter?

Unfortunately since I just got her I have no idea what her normal behaviour/personality is and have nothing to compare it to.

Do these sound like it could be a second known pregnancy, or should I just keep my eye on her before rushing out to get kitten food for her?

Oh and I can't take her to the vet's, I am a college student in Northern Ontario and they are simply very unaffordable. She'll be kept strictly indoors until I can get down South to my normal vet. Sad to say that the prices are at least partly why the feral cat and dog population is so huge here.  

Sorry for all the questions haha.

Count on she is pregnant.  Cats arent protected from new pregnancies by nursing kittens, unlike humans who are somwhat protected (not 100% but still).

Are you sure there arent any low price spaying clinics around your place?   (Ontario is in Canada, yes?  In that case our lists on USA-based places wont help).  Try and ask shelters around...

Or rather - if you had access to a low price spaying clinic, would a spaying / abortion NOW be possible for you?  Quite a few people are very reluctant, unless the mothers life is in real danger...

Good luck!    @phloxy

Yeah, sorry should have clarified lol- Ontario, Canada. But no there isn't anywhere nearby that I can afford, the difference in price is over $350. If my friend can drive me there is a spay/neuter clinic a few hours away though you need to make the appointment months in advance. I'll call and see if they can squeeze her in though. If not I suppose I'll be coming on to ask questions throughout the pregnancy haha!

Thank you for the input.  

Hello. Just wanted to update that I am unable to get to the clinic to get my girl spayed. Still am uncertain if she is pregnant, but my roommates mentioned that she does indeed look rounder so I'm assuming she is. Any help and hints will be greatly appreciated!