On Kundalini 2

I sit and close my eyes. The mind wanders for a bit.
I remind myself, ‘drop away’.
Then it starts.
That now-familiar shaking from side to side at the bottom of my spine. It works its way up the spine and the movement seems to get bigger and bigger.
If I start to think, the shaking stops.
Also, I can stop it if I want to. (If I’m teaching or participating in a yoga class that’s usually what I do.)
But if I just want to meditate, I let it continue and finally my head is shaking rapidly turning side to side. There is also usually a lot of heat. Then usually after a little while that is enough and it stops.
There is blissful stillness for a while.
So who is doing the shaking?
Certainly it is not a conscious decision that ‘I’ make. In fact when it started almost a year ago, I felt the couch I was sitting on move before I realized the movement was coming from my body.
The state that it seems to take me to is that blissful meditation state. I arise from meditation feeling peaceful, connected and energized and everything is OK with the world. I find that dancing and chanting also can take me to that state of flow where everything seems in-sync. Out of the thinking-head-space I suppose.
Into the intimate experience of Union with the divine.
I don’t know anyone else personally who has kundalini experiences like this. 
Anyone care to share their kundalini or meditation experiences?