So my best bet for this little guy is to wait to see if it's barred?
I'm glad I asked, I totally thought that females had dark spots! This is all great to know!
Yep! You should be able to sex it that way as long as it doesn't feather in white. The white masks the barring. I have a white leghorn I didn't know was barred until I hatched a little sex linked cockerel from her eggs. Couldn't tell he was sex link until the wing feathers came in barred.