Constant Throat clearing. With time.

Hello I am having a constant throat clearing from last 20 days,i have visited general physician he prescribed me antibiotics & paracetamol,done with the course,but did not stopped,then i visited ENT he prescribe me rabonik+sr capsule & monticope tablet,after this also same throat clearing is happening,i have done sonography and x ray both are normal.also done full body blood test that is also normal. Is this a habit or something is really wrong.Beacuse when i am busy some-where it happens very less. I feel like clearing throat and mucus comes out & mucus is white & normal. Also after drinking water & eating something it happens more. Any advice will be highly appreciated. Also this throat clearing last longer or it will go away with time.