This is my first time incubating eggs, and so far it has not been textbook. One came on day 18, one came on day 20 and now on day 21 I have 1 chick that does not seem to be able to get out of her shell. Instead of pecking around the egg she consintrated on one hole. You can see part of her, including an eye and her beak. Should I be worried? Its been 12 hours! She has a strong cheap and her eyes are open.