Hi H,

I really wouldn't consider changing my racial/ethnic/census designation based on the results of a Biogeographical Analysis (BGA) and especially NOT based on Ancestry's BGA!
Please read Roberta Estes' blog post: Proving Native Ancestry Using DNA http://dna-explained.com/category/biogeographical-analysis-b...
which explains BGA and other dna testing.
Hope this helps! :)