Still looks like yolk sac to me. Not ready to hatch yet those veins are still red and active. It needs more time. Also try not to let it burst the sac or rupture any of the veins.
To me it does not look ready yet. I can see red blood.
If the whiteish area is attached to its navel it’s likely to be the the yolk sac. This needs to finish absorbing. Can you put some Vaseline on the membrane that’s left and put it in the incubator to finish off. ideally it needs to stay in...