If Indian ancestry has been suspected in your family but you have never been able to track it down, there is a chance you might be Melungeon, instead. A long time ago, persons who had darker skin liked to assert that they were "Cherokee", and this misunderstanding persisted in family lore to the frustration of those who try to find where it comes into the generations. The surnames at the above-referenced site are common among Melungeons.
Wikipedia has more information about what Melungeon means: