I walked out of the school and was watching a plane and noticed something smaller fly past it heading the opposite direction.

I had just walked out of the School when I saw an airplane and stopped to view it. Then I noticed a smaller object fly past it, heading the opposite direction. I could see the wings/fins of the plane but not the other object so I took a picture and second picture on accident. I was trying to record but wasn't able to in time as it flew past and my school building blocked it. I reviewed the photos and zoomed in on them further only to see it was a disk without any kind of wings or fins.it seemed Grey and it was over a clear blue sky. Even stranger is that in the second picture I took I noted it seem the width had decreased and wasn't as slim? Could be the angle. I'm not sure.