Not sure if I am seeing it correctly or not but we had a SF rooster one time and if you see black feathers coming in on the chest/breast it will be a rooster. If the feathers are white or buff then it is a pullet.
Can you give us an update or a picture from the front? If not I can dig out pictures of our little guy when he was about the same age maybe a week older than yours.
Good luck either way with your sleepy little fella!