chickens don't usually start eating eggs unless they have a reason to start... like a dietary deficiency, or if one gets broken by accident and they decide to taste it. I personally would think three days is no big deal and things will go on as usual. You'll just have three days' of eggs to collect when you get back. Also, they eggs won't be bad because eggs can be kept for a long time without refrigeration. I know people who have done it way longer than 3 days. If I were you I wouldn't worry. I doubt it would make any of the girls go broody either. But, if one decides to... just take the eggs away when you get back and hope that she didn't get really well settled. I bet it will all be fine. I wouldn't worry at all if I were you. Enjoy your time away!