@casportpony is exactly right, candling and checking your broodys eggs will not harm them... I check on my Call duck broodys eggs all the time and they have excellent success with good eggs... if they quit or go bad, not even a broody will be successful with those...
I was thinking they might have been late quitters as well, but if you saw movement, then they're still viable... looks like they are close to hatching, within next couple days or so... hang in there and good for you putting your broodys health first!