A beer can be finished at ANY gravity. A lot of beer finish at 1.020. A beer is finished when the gravity stops dropping, NOT necessarily by the number it is finished at. I have a barleywine that is finished at 1.040, but it's starting gravity was 1.170, so although it seems like a high final gravity, in terms of the beers style, it really isn't.
Take another gravity reading in 2 days, if the number is the same, regardless of what number you think it should be, then it is.
There's nothing wrong with 1.012