Ducks are like chickens, they don't lay every day. I've noticed particularly with my cayugas cause they lay a green egg I may get an egg a day for weeks then they won't give me but maybe one egg in the next two weeks. Not sure why but they are pretty sporadic.
Make sure they have lots of water. It tends to help them crank out the eggs.
Make sure they have lots of water. It tends to help them crank out the eggs.