I did my candling on day 5. I had 4 of the 28 eggs that I started looking just like the one in your photo but, the other 24 very clearly showed the blood veins. I am on Day 8 now and I just did another session of candling. All the eggs show a complete web of veins and the start of the chick to the point that you can visibly see the eye of the chick. If the temperature of your incubator was only at 96 degrees you may need to start fresh and try again. For the best results, run your incubator for 24 hours at a constant 99.5-99.9 degree temp. If you have a humidity option you'll want your humidity between 55 and 60. When you place your eggs in the incubator DO NOT remove the lid or open the incubator for at least 24 hours. After the first 24 hours if you hand turn your eggs you'll need to do it as fast as you can and not have the eggs open to room temp for more than a minute or two until at least day 5. That is a pretty decent time to noticeably see if your eggs are fertile or not. Look for the blood veins.
Hope this helps!! Good Luck!!