I Am Now 20 Years Old And Have Had 5

I am now 20 years old and have had 5 kidney stones in 5 years I have a question that I am searching hard for now. Why doctors say if a kidney stone is not obstructive it wont cause pain. well I disagree with this, yet I am open minded to this however my last urologist could not explain my question if a non obstructive stone does not cause pain..my explanation to him was at 15 years old I had a stone for over a year that got to 10mm that entire year I was in and out of hospitals with massive pain in my kidney yet, they didnt even see the first stone. Now with my 5 stone im still in pain not always however it can be sharp and happens atleast one a week. My doctor tells me it is not possible however I feel this pain is always been the same and always in my kidney. yet I have had surgery on both kidney only one side hurts now..I went to the hospital and low and behold I have a 3mm stone forming in my left kidney where my pain has only been effecting me in my left kidney. How many receptors are linked to the kidney?