Bloody Mayhem

If I'd ever had the slightest inclination to read any of the Twilight series, Julie D. has effectively cured me. However, I do read movie reviews, and here's a snippet from Thomas Hibbs' take on New Moon:

In New Moon, Edward decides to end the relationship permanently after a paper cut on Bella’s finger during her birthday party at the Cullen home has nearly tragic consequences. Unable to rid the world of the threat of paper, the Cullen family leaves town.

What, exactly, do the Cullens do when Bella is on her period?