Is this cat lost - possibly injured, even pregnant?

[Amélie]

Hello there.

One night I had returned home from being out with some friends fairly late at night.

I live in England, and in my neighbourhood around a week ago there was a rather straggly looking cat, with no collar, sitting on the driveway of my neighbours house. I sat on the wall a short while gently talking to the cat who looked scared, and quite alone. I have no experience of cats, other than friends family pets etc.

Slowly the cat approached me and gently purred whilst reaching up it's head for me to stroke. There seemed to be no aggression in the cat at all, and I inspected it from closer. I got the feeling the cat was female.

She had scratches across her nose and dirt around her back and sides of her legs, and when stroking her she felt very bony. I noticed a sort of lump around her stomach, which I avoided touching in case this was painful to the cat. As I have no experience of cats, I was unsure as to whether she was ill, with a tumor or perhaps pregnant? This could just be me being naive.

Anyway, last night I came home again fairly late and the cat was sitting there again, with more scratches on her nose, still looking a little dirty. I figured the cat could be lost? I went inside and had a quick look around the kitchen to see if there was anything cat-worthy, and found some tinned mackerel.

I offered the cat a small amount, rapidly she ate it without hesitation and looked up at me. I got a small amount of water, which she didn't seem interested in, then tried a little milk which she drank quickly too. As I went back into the house to put things away she followed me into the garage before going back outside. I shut the door slowly and she poked her head through the door. I checked out the window before going to bed and she was still laying under my dads truck on the driveway.

Basically I'm wondering if the cat could be lost? I know the cat is obviously going to go where there is food, however I get the impression she is lost, pregnant or possibly injured?
I don't want to interfere too much, as the cat could have a home?

Please give me your opinions and let me know what you think I should do if the cat returns again.

Thanks very much,

Amélie.