From The Free Dictionary
egg on (one’s) face Informal
Embarrassment; humiliation: If you do that, you’ll end up with egg on your face.
lay an egg Informal
To fail, especially in a public performance.
put/have all (one’s) eggs in one basket Informal
To risk everything on a single venture.
Why is the egg so often associated with failure, or the threat of it? To lay an egg is at the very least a creative act, and at best a source of new life. There is certainly a parallel here with writing: both the creative impulse that produces it and the danger of disaster if the effort fails. Eggs are fragile, as is the psyche, and a broken egg is, after all, a major mess. But, oh, when it works it is glorious.
More on eggs next time. Now, breakfast.