As most Potter fans know, a Mudblood is a nasty word used to describe a witch or wizard whose parents aren't magical, and the centaurs roam in the Forbidden Forest in the grounds of Hogwarts.
Last year three rumoured Potter titles came out, and there were even rumours that an eighth book was being written.
But JK said that wasn't true, and added that no-one knows what the titles of the remaining books are, except for her of course!
Newsround's tried to find out what's going on, but at the moment Warners and JK's people aren't making any comments about it.
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Talk Potter!
Secrets looks AWESOME!
