Actually if it did pip two days ago and there has been no progress since, that is an indication that it may need help. I am not seeing any blood in that membrane; if that is correct, it may be ready to hatch. Is it struggling or pushing against the membrane? Is it making any yawning or chewing motions? If yes to the first and no to the second, you might want to gently peel the membrane back. Of course, stop if you see any blood.