According to Bruno Bettelheim in The uses of enchantment, pricked fingers in fairytales symbolizes menstruation as a precondition for conception.
“The story begins with Snow White’s mother pricking her finger so that 3 drops of red blood falls on the snow. Here the problems the story sets out to solve are intimated: sexual innocence, whiteness, is contrasted with sexual desire, symbolized by the red blood. Fairy tales prepare the child to accepted what is otherwise a most upsetting event: sexual bleeding. Without detailed explanations the child learns that without bleeding no child – not even he – could have been born.”
Well, I’m certainly not preparing myself for another child, my fingers are bleeding purely due to trying to embroider on rubber…..