On some of our chicken hatching eggs, on day 10 we saw veins. Now it is day 16 and we can't see veins anymore but there is an air cell and a chick. My mother said that the chick died and now she wants to discard the eggs with no visible veins because she said that the chick died in the shell. My question is does the veins disappear just vanish when they were there when the chick dies? Shouldn't we keep the egg?