Thanks to Gumpsgirl, Farrier!, silkielovr,justmeandtheflock
and all who added to my question. I have broken open my eggs and checked for the "bullseye", to find a very large % of fertile eggs. After they don't hatch I don't open them.. I don't think the smell and I would do well together.. I throw them away, very carefully.
The link w/the "bullseye" pics are great.
I have hatched my own eggs, and had great hatches, then bought eggs, had great hatches, and 1 or 2 hatched from shipped eggs. I just think maybe sometimes, weather changes, do affect my hatch rate, temp., humidity, post office. I have shipped eggs, the buyers have had good hatches, bad hatches.. We never know, what happens in between. I am sure not complaining.
I just wanting to make sure there was not a secret to knowing if the eggs were fertile... w/o opening or putting them in the bator.
But, I figure that is a gamble I have to take to have different lines of chickens from fellow BYC. It is fun. BYC'ers are awesome. And I am just trying to learn.
M