I'd try it Ponylady, the hatchability will certainly be dropping off but i'd still give it a go, they may well still hatch.
Store the three spare eggs at room temperature, 15C is perfect, no less than 10, no more than 20
Store them point end down, if they're stored like this they don't need turned every day, its only if they're stored on their side they need turned.
Actually the best way to store them is point upwards, it'll give you a slightly better success rate.