Its too soon if the egg was laid on Dec 2nd.
Unless there is veining around the pink dot, it probably isn't fertile.
Here is a picture of what I mean by veining:
The pink dot in this pic is the embryo. The veining will start near the embryo and work its way around the egg until it covers the whole egg minus the air sack.
Yours does have the pink dot (embryo) but there are many variables that can prevent them from developing. So if it was laid and placed in the incubator on Dec 2nd, it's only a few days old and too early to tell if it's definitely a fertile egg or not. Some will start out with a pink embryo that you think is fertile, but it will stop growing. It can get darker as you candle it because it will eventually start to rot. These usually become "bomb eggs" and you will want to remove them from the incubator as soon as you verify that it's no good.