I did a DNA test last fall for Native American test plus ancient ancestry. Unfortunately, the Native American test could only verify safely back 5 generations and my 2 probable Indian lines are back further. Perhaps the new science will be able to determine further back as things progress. Also, last month 23andMe started another option to find relatives using autosomal DNA -- does not have to be just paternal line Y-DNA or just maternal line Mitochondrial DNA.
There is a great sale going on for new kits -- expires 31 March -- 1/2 off. $200 savings. See -- https://www.23andme.com/partner/foa/
They send a kit in the mail which is basically a tube for saliva collection -- just spit into tube and return.
If you do the test, then you would know your paternal (if male) and maternal line going back thousands of years. (The men have Y chromosome, so can know their paternal line).
The relative finder option is also very interesting. They are claiming able to find relatives back 5 generations or 3rd cousins. And I found a 3rd cousin once removed -- descends from my German great great grandparent. Relative finder does also show possible 4, 5th cousins which could be 10 generations back or even further.
This DNA testing for genealogy as it evolves could be a boost like email and internet is.