looks good. I've grown MI5 and mine showed sex at 2 weeks like clockwork on 18/6. I'd start looking for balls now. I'd be surprised if you didn't have signs already.
For the record, some of my MI5's ended up at only 12" tall, while others topped out at almost 30". No rhyme or reason.
Looking good, I see more than a few grams in your future, alot more!