Black disk flew past a fighter jet and passed the sky in less than one second

There has been fighter jets out so I went out to watch them. (I live near westover afb, so it's normal) A black hawk had just flown over and I was recording a fighter jet and plane with Chemtrails in the sky. I didn't notice any extras sounds except the original fighter jet, but I saw a larger (than the fighter jet) black saucer-like object fly super fast past the fighter jet and out of visual range. In checking the video, it's at the 48 seconds timer, enters on the left side, and is off screen in less than one second. It was gone so fast. In the video, there is a shadow/ visual mark of something else behind it, but I don't know what it is either. I uploaded a snippet of the video because your system doesn't let the whole video.