I saw a matte black long flat pyramid that seemed to hover in the sky. I ducked under the window and when I looked back up it moved away

It was very dark so I did not see it very well, but I saw a jet black flat pyramid that was hovering but slightly moving left to right as it was staying almost still. I freaked out and ducked under my windowsill, and when I peeked back up it started to move away. It almost looked like it was changing shape but it could have been the change of perspective as it moved away. It was about 15 meters off the ground. It seemed to somehow glow as I should not have been able to see it because of how dark it was, so it was widely luminescent. The next day I woke up on the floor of my living room, and it was a Sunday, so I skipped a day. I didn’t question it as I was very scared and tried to act normal so I did not tell anyone. I don’t know if it abducted me or something but I missed a whole day.