I've only got two certified rides under my belt. (COVID really threw a wrench into my plans.) Both of those certs arrived in the mail a few days after I got the invoice and paid for them. I don't recall the exact shipping time, but it was definitely less than a week. If I were you, I'd plan on a week of transit time and be happily surprised when it arrives ahead of schedule. Oh, congratulations on the ride. They are tons of fun aren't they?
Like Tom said, the waiting is the hardest part.