Oh you sound just like me last year! First time mommy, and I was a wreck! Heaven forbid anything in nature ever survives without human intervention! I have been known to cover monarch caterpillars in the rain..... I am going to intervene a lot less with this go around - she has proven to be a good momma hen. I think if momma is being a good broody - you have a very strong chance you will have chicks. Mine came a day early last year, but I had a few eggs that did not hatch - the ones I was really hoping for of course. I gave it 2 or 3 days past the due date, and then took them out. Upon inspection, not one of them was viable. I got 4 chicks out of 7 eggs....ended up with 3 roosters! If you don't get any chicks, check around on this sight about how to put day old chicks under momma - she will most likely accept them, and raise them if that is your end goal. Keep us posted!