Sexing question

So I have 4 plants from seed right now a lil bit more than 2 weeks old and I figure I'm going to start sexing soon and I was wondering if there is a certain node I should look to first or is it just random?

um first question, why are you sexing at just 2 weeks old? are you doing straight 12/12 or are you goin to be vegging for a while? you dont sex until you flower em, and yes you want white hairs not balls, my suggestion is to read just about everything you can on this forum and get some knowledge before you try a grow good luck