yes! when you flowr a seedling (not a clone) with only 4 or 5 nodes it will often take more than 2 weeks to show its sex... early flowering can be done.. and very sucessfully... and is recommended in cfl lighting scenarios.

if you look in the basic growing forum, you will find a thread that I started that says something like "this is what a healthy 2 week old plant looks like"... this thread will show you pictures that will answer all your questions... : ) regarding flowering seedlings with 4-5 nodes...

iloveyou