Pekin?

[Suezp]

I got 3 what I was told pekins from Tractor Supply . They are now 5 weeks old and all three are white except for the black patch on very front of its head, do pekins have some black? thing they got these ducklings wrong?

 

[TheFinalGirl]

This happens! It most likely means he is a mixed Pekin.

 

[TLWR]

Do you have a picture? Could be a different breed.
Sometimes yellow ducklings are hard to tell breeds.