White crested black Polish

[Mbart83]

hello! I am trying to determine if my 4 week old (hatched 3/5/18) is a roo or pullet....as a baby I thought pullet, but now I am not sure! Any guesses welcome! And appreciated!

I included pictures from a couple days old until today.

 

[HuskerHens18]

Right now it's crest looks like a pullet, roosters have long crazy hairdos around six and seven weeks it's easier to tell. Before then nothing can be certain