We have 4 RR hens and a BR rooster. For the last 3 weeks a broody hen has been sitting on the eggs and so far nothing has happened. She started off sitting on 3 eggs and now there are 5 there. She comes down to drink and eat and then goes back to sitting on the eggs. We figure at least one egg has to have been fertilized? Is there a good way to tell if an egg is about to hatch? She gets very agitated if we get too close. We can see the eggs when she is out of the coop eating. They look normal.