The eggs are not going to explode because the embryo is dead. That is a common misconception on the forum. What causes an egg to explode or go rotten and seep a foul liquid is bacteria getting inside and multiplying. It doesn't matter if there is a live embryo in there or not. If there is a living embryo in there when bacteria invades it will kill the chick. So do not feel any extra pressure to get an egg out if it is not developing because it will explode. It will not unless bacteria gets inside. To me the best test to see if an egg has bacteria inside is to sniff it. That rotten egg smell comes through the porous shell.
I cannot see any veining in that egg. Veining is what I'd look for at that stage, not movement. I can have trouble seeing inside my green eggs and often do not see any movement. It is quite a thrill seeing movement but I hardly ever remove any egg until I candle at lockdown for any reason. Then I remove the clears. Not because I'm afraid they are going to explode but to make it easier to follow the eggs that are pipping and hatching.
What you want to see at lockdown is a pretty solid mass in the egg but with a good air cell, but if an egg has much development, even if it is not a solid mass, I tend to leave it in. I do not worry about whether I see movement or not because sometimes I don't and the egg still hatches. Especially your first time candling, don't do anything rash.
