Flying Disk seen approx 150 ft above ground near Randolph AFB

This is a sighting I had as a child and to this day still see it in my mind like it was yesterday because it was such an overwhelming experience. it was approx 1965 before I was not quite old enough to go to school and i used to always go outside to look down the road to see my brothers and sister coming home from school. We lived in what was called Riedels trailer park in Schertz, TX, off of highway 78. My dad was stationed at Randolph AFB and it was only 1.5 miles down the road. This one afternoon I went outside to check if my siblings were coming down the road home and glanced up in the sky between the trees that were on each side of our road and approx 150 FT in the air was a whitish disk sailing through the air with no sound. It was tilted on its axis toward me like it was making a turn. I froze and followed it through the air which was about 15 secs when it became obstucted from my view by the old Starlite theater screen we lived directly behind. i have told a few people in my liftime and the best i always described it was like it was made out of concrete, the color description it looked like. It was approx i'd say 50 ft in diameter and approx 8 to 10 feet thick. it was like a giant nickel but whitish color. there were not any markings on it i could see and no windows. I never heard a sound. The weather that day was clear and i was i'd say approx 1/4 to 1/2 mile away from it as it seem to make an arc in flight around me. I rushed in the house and told my mom but she said i probably just saw an airplane. I was about 4 to 5 years old at the time. I would have to assume that alot of people would have seen it since it was so close to ground and good weather. I havent seen anything in the blue book files about it; you'd think you would since it was right by the air force base. The object left no trail or emitted any kind of light either.