What are the odds?

I've gotten into the habit of making myself eggs for breakfast. I had a carton of 1 dozen eggs. So far I've used 6 of them. Out of the six I've used two of them have had double yolks! Bizarre, right? I've only seen double yolks a couple times I can remember, and now I've seen them 2 out of six times I've cracked an egg open. I don't know the odds of this happening, but they've got be impressive... don't you think?