A silver orb seemed to hover and move in and out of the upper level of a large cumulus cloud.

When I was 7 or 8, I was very much into distance running.  There was a 1.1 mile loop that I ran several times a week.  
On a cool day sometime in the spring I was running up a large hill near a local middle school.  I looked up at a large cumulus type cloud and noticed what looked like a tiny silver sphere hovering next to the upper right part of the cloud.  It was very shiny, reflecting the sun like a car would on a sunny day.  
I immediately stopped running and stared at this object trying to figure out what I was looking at.  I could tell the cloud was moving slowly towards me, but the object seemed to remain stationary.  
After a few moments the object moved to the left, appearing to go inside of the cloud.  It stayed hidden for a few seconds, then moved right and again hovered in the same spot.  
I watched it for a few moments, and it seemed to begin to move vertically very slowly.  Then it again moved left into the cloud and didn't emerge for what felt like several minutes.  
As I began to run again I looked up one last time and saw a brief glimpse of the object as it moved in and out out of the cloud on final time.
Source of report indicates that the date of the incident is approximate.  PD