First off, fertile eggs aren't a problem. You eat them just like unfertile eggs. No one can tell the difference.
Okay, what type of sex links are they? Where did you get them? If they are hatchery birds and you got them from a feed store or hatchery you can sex them easily. If they are some red based sex link--red, gold, brown, etc, and the bird is mostly that red color with some white feathers on the back end, like they were dipped in bleach, they're hens. If it's a mostly white bird with some red only on the shoulders, it's a rooster.
If they're black sex links, if it's solid colored it's a hen. If it's barred, it's a rooster.
That's the joy of sex links, you can sex them easily just by looking at them.