small saucer zipped down over mountains, hovered, and zipped down Fraser Valley during daylight hours

I was washing the dishes after school at about 4:00 in the afternoon, looking out of the window at a panoramic view of Vancouver with the mountains behind. It was a clear day with no cloud cover or smog. Suddenly a disk-shaped craft, not very big, zipped down over Crown Mountain in a curvilinear movement and hovered over southern Vancouver, directly in the center of my vision. There was no sound or fumes, and, although the craft was clearly technologically skilled in design and fabrication, it was equally clear that there was a sentient being controlling it, as it moved with choice and a certain sense of style, and not in a robot-like way. And although it was still quite far away from my window (approx. 2 miles) i felt uncomfortable by the way it was hovering so deliberately in front of me; as if it was looking directly at me somehow. That was just my subjective feeling, but i record it in case others might also have felt that way.
Before i had a chance to draw my breath and yell to my family, the craft zipped off again, down the valley, going at an incredible speed. The total distance covered by the craft in the space of under a minute (including hover time) was approximately thirty miles.
At the time i was 12 years old and not under the influence of drugs or alcohol, devout and not given to lying. I thought i had witnessed an experimental American aircraft, but have not seen anything like it since.
Just wondering if anyone else in the vicinity might have noticed it also.
Date is approximate.  PD