I guess B. Grunt and I have been tag teaming this problem. He knows his shit too.
I'll give you a rundown as your flowering question never got answered.
You should start to flower when alternating nodes appear. (I have had a bagseed once that never really alternate which was wierd). So I started it at 1.5 months. To start flowering switch to 12 hours on and 12 hours off lighting schedule. Get a timer, there cannot be any interuption of its dark schedule. If you do, this will hurt yeild and potency. This will get smelly, so consider ways to keep odor under control. Even if your parents are cool with it wait until the house starts gettin that dank smell. They'll change there minds quick.
Read up in the links in my sig. lots of useful info there. Listen to B. Grunt and other members that have been around for a while. Lots of smart people around here.