They May Have Your DNA...
It's very possible that the FBI has your DNA on file. Not because you did anything wrong necessarily, but you could have submitted your DNA in a way that fell into the hands of the bureau. Ancestry DNA tests became very popular, and the companies have sold the DNA samples to the FBI.
This has actually solved tons of cold cases by using genetic tracking. Don't worry, the company must ask your permission in the contract! It's really not as big of a conspiracy as some people make it out to be.