‘Tis the season of Odd Eggs. This type of egg usually appears at the beginning of the laying season. The shell hasn't been formed properly and this is not one to be eaten! A chicken may also lay very small eggs, perhaps with no yolk, or ones with extremely brittle shells as their system hasn’t got going properly yet.
A “lash egg” as it is commonly called can be the sign of an infection in the oviduct system. They look slightly different to this one, may be very irregularly shaped and contain bits of gunk and solid matter. Otherwise, if it's just a shell issue as this one is, then as the laying season gets underway you should see normal eggs start appearing.