ducks are nesting help!
It is still possible for the eggs to be fertile. Females can lay fertile eggs for several weeks after being with a male. It would be worth a try to toss some into an incubator once you have gathered enough. I wouldn't wait too long, though. Maybe gather eggs for about 7 days and then stick them all into the incubator and see what happens. There's no guarantee one of your females will go broody in time to incubate these first eggs that might be fertile. Good luck!
I am one of the ones who has food and water available to my ducks at all times. They should at the very least have access to water 24/7. They are water creatures after all, and I don't think it's right for any animal to be without water. I know there are alot of people that do not give their ducks food/water overnight, but I just don't agree with that. It's everyone's own choice, though.
You can try, but alot of ducks don't seem to ever go broody. They're not as good as chickens in that respect. Since you have very limited eggs that might still be fertile from your males, you might lose them if they are not incubated soon enough. Egg hatchabililty starts to drop after they are 7 days old. It's drops significantly after 10 days.