Are you seeing a credit or debit card charge from Blurb that you don't recognize? If you recently ordered a 23andMe ancestry book, note that Blurb fulfills those orders. This means you'll see a charge from Blurb for that purchase. (You can read more about the Blurb and 23andMe partnership in this 23andMe blog post).
If you still have questions about Blurb, or a charge you're seeing from us, please contact customer support and we'll be happy to help.