A bun in the oven- euphemism

When you hear, "There's a bun in the oven!" what do you think? I know before I knew what this euphemism was I used to think, "You're making bread?! Why are you so happy about that?" In reality when someone says 'A bun in the oven' means you're pregnant. This euphemism comes from the 20th Century, an example is, "I bet you left a bun in the oven, both of you,' said Bennett thickly." (Monsarrat 1). This quote comes from the novel 'Cruel Sea' published in 1951. The bun represents the baby and the oven refers to the womb, so the next time you hear this euphemism, don't expect any bread!