I have had this egg ,that I don't know what it is, for a really long time
Certain eggs have certain steps
A Rattata egg takes a minimum of 3840 steps to hatch
A Murkrow egg takes a minimum of 5,120 steps to hatch
It all depends on what type of egg it is. it also helps if you have a pokemon in your party that has the ability flame body, it helps eggs hatch faster.