can anybody tell me how the adbrite works..?

many of you, own a blog with ads to earn, even CE has ads, I have a blog..I'm using adbrite alone.. My blog reached the minumum check amount , faqs in site are telling that it might take 3 months to receive the check..I really dont understand how it works..

if MY Nov month earning is 15$, and my minimum check amount is 20$, in Dec month the minimum check amount reached means, when will I get money..?