Pain right side of stomach?

i have a pain right side of my stomach its a light pain but somtimes it can be a sharp pain it is worse when i am lying down on my right side i dont get sick but i do be very tired for no reson at all i mean i get my eight hours sleep plus i cant stay awake all day i have to sleep for about 2 to 3 hours every day i am like this now for the last 2 years i have done ultra sound and clonscopy found notting i dont drink just smoke any idea what the pain might be tks