Definitely boy! That's a good nub shot! I've been studying this since my scan 2 days ago!
I'm pretty sure mine is girl. I have a. couple pics with a bright white line, one is parallel and one is down. I have another pic that is harder to see the nub, but piety sure I can pick it out because I definitely see the nub on the other 2. I'm going to switch to full site so I can post. Would love ideas!