Refer to incubation and hatching eggs. There is a sticky there about how to tell. I will say this, the only.way to know.for sure involves.cracking one open and looking at the yolk.
You have to crack them open. There's no way to know without opening the eggs.
On the yolk, where the white spot is, there will be a white "bulls-eye" circle instead of a solid white dot.
Search "bulls-eye" here on BYC and you'll find plenty of posts about it, including some with actual photos of same. I think if you check the "sticky" notes at the top of the Incubation and Hatching forum, there's one with those photos.