Amy: I travelled with you in this TARDIS for so long. All that time. If I was pregnant for some of it, wouldn’t it have had an effect? I don’t want to tell Rory, this baby might have three heads, or like a time head or something.
The Doctor: What’s a time head?
Amy: I don’t know, but what if it had one?
The Doctor: A time head?
Amy: Shut up, all right!