Thank you very much for your answer, it is really appreciated.
Indeed it is a little bit hard to completely stop worrying although I know rationally that I should. Anyway, the rational thing would have probably been to stop after the negative Western Blot at 13 weeks, but I did not and hence the two indeterminate.
To answer your question, I was born in Canada and I, as well as my parents, are whites. To my knowledge, I have no known ancestors of different ethnicity.