Well, having spent a couple of hours this morning watching very quietly I can now confirm that I do indeed have three pigs, and furthermore they have names!
Cobweb (black with ginger patches) - definitely the alpha female. Steals cucumber from...
Mustardseed (ginger with white patches ) - seeks Cobweb's protection when venturing out.
Peaseblossom (white with ginger patches) - timid but seems relatively independent of the other two at the moment.
No pictures as yet though.