I have 5 duck eggs (1 Jumbo pekin, 1 welsh harlequin, 2 white crested, & 1 cayuga) in my incubator. It has been 31 days and they have not hatched. I am trying to be patient but I no longer see movement in 2 of the eggs. I am using a new incubator this year (Brinsea mini advanced). Any suggestions? I would hate to loose all the ducklings.