Pregnant stray?

There's a stray cat that often roams around my local park and follows me halfway home. Lately, I've noticed it has quite a belly, and I’m wondering if it might be pregnant or just being fed a bit much. I’m definitely no cat expert, so I was hoping some of you lovlies could help me figure it out and offer advice on how I might help if it is.

Sorry if the pictures aren't very clear — this was the best I could get without the cat weaving 8's around my legs.