My ducks have two nests. The one mama duck didn't start nesting until she was done laying. If they are brooding, you will notice a lot of eggs in a few days. They usually don't start sitting on the eggs until they have laid the whole clutch. It took my mama duck about four or five days. Last count I had was 17, she hardly leaves the nest now. They all may be duds, we shall see. Closing in on 28 days now. I don't mess with her nest. I let her do her job. If we have little ones hatch then we do, if not I will throw them out. Give it time love.