Is Lulu Pregnant?

I just adopted Lulu less than a month ago from a family that posted an ad on Craigslist. They never did say why they wanted to give her up, but when I got to the house there were like 5 little girls all clustered around her! Well they said she was 8 months old and not much else, except she doesn't like being kept on the floor and to feed her. I fell in love at first sight and nothing was never the same. I had never cared for a guinea pig before, so at first I was concerned that she was eating sooo much! She went through the zip-lock bag of food they gave me in no time, and she went crazy for the timothy hay. I added a playpen on to the small cage they gave me, and she mostly stayed in her cage and really didn't enjoy being picked up! So I started doing research like crazyness.

Now I think she might be pregnant. At first I shrugged off the idea because the owners had told me she was kept alone, but then she just kept on getting bigger. Is there any particular way of knowing for certain? I'm rather concerned because she is now 9 months old and is very antisocial, it takes her a long time to warm up to a person and when I tried to introduce her to my mouse she bit her! Just in case she is pregnant I've been making sure she has veggies every day and fresh hay, pellets and water at all times, not to mention I clean out her cage almost every day!

So here go the questions:
1. Do you think she is pregnant? Her owners said she was not housed with males, but I don't know them personally, and they only answered me in a one-word email.
2. If she is pregnant, is there anything I can do now? I found I can't afford a single exotic vet right now, or for maybe the next month (college student :sad but I want to do all I can for my baby girl!
3. If she has babies, how much would it cost to neuter the boys (if there are any) and could I keep them all in the cage/pen structure with her?
4. Should I upgrade to a C&C cage? Though I lack room or funds, I would be happy to build her the cage if only I could find the materials in the area. They don't have it at Target, and the closest Wal-mart is 20 miles away (I live in Montgomery County, I heard they banned Wal-mart).
5. Is there anything I should do to make her comfortable? I attached the excersise pen to her cage and laid out a rug inside it, I line her cage with newspaper (trying to be econimical and eco-friendly) and fill her litter box with shredded newspaper. She has an igloo and I always keep a pile of Timothy Hay around.

For added measure I took pictures of her (the best I could get she doesn't like being held much especially since a few days ago for some reason!)