I just recently heard somone else had this in the Live Chat, Im not sure what it is but Im gonna suggest it may be the strain, or your plant just wants to be a badass, which Im sure it will be. But my best guess is genetics.
looks like in the middle it will be another set of leave leaves haha or maybe six idk but im excited ill keep posting pictures when it gets a little bigger
The type of mutation you see in your plant is discussed here: http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/P/Polyploidy.html. MJ is usually a DIPLOID plant, giving two stems per node, opposite each other. POLYPLOID plants carry a mutation such that the plant adds one or more to this number. So you have a Triploid Cannabis plant. Wait a bit and take clones. They should all be that way. And then please send me one. It may grow bigger than the diploid variety so be ready for it, space-wise...