Early Pre-Flower

Hi guys, this is my first time growing Cannabis, and I'm totally a noob, my 2 months old plants which are around 5-7" tall are showing pre-flowering signs, one of them growth pistils the others I'm not sure yet ! But Isn't it too soon for pre-flowering ? are my immature plants going to flowering phase ?

No, they should be ready and mature at eight weeks. Indica hybrids usually show for me at around six weeks.

But they are very small to be a mature plant ! How much is the gap between pre-flowering and flowering ?!