I am new to chickens, so please don't laugh at me if this is a stupid question. I have a pullet and I used to have a cockeral (before he started to crow). Is there any way that the eggs are still (if they were at all) fertile? I got rid of him in February and she didn't even start laying until March. So I don't think they are fertile, but I noticed that there was a little white circle thing in the yolk when I cracked the egg open. I have no idea what it is. Is it normal? And how long do the eggs stay fertile after you remove the roo from the flock?