Frequent visible vibration in my head.

From past 15 days I have been noticing frequent moments in my head on which i don't have any control. It feels like vibration and if you look at my face with focus then you can tell that it's moving slightly left-right frequently. I don't have any control on that. During my sleep also i felt that. Many times in nights also this happened. I don't have any headache or anything. I'm not feeling nothing. I'm normally doing my daily work like before but out of the blue at any time my head start vibrating. Mostly it happens when i sit idol doing nothing. Specially in night. I'm confuse regarding these symptoms as I never heard or notice this before and I don't wanna google it to exaggerate. Need some help. At least i need to know that to whom should I contact? Which kind of doctor will help me?