I have experienced astral projection once in my dreams. It just happened. I didn't do any practise before, whatsoever. I saw myself sleeping for 2 seconds and then woke up right after. If somebody has experience with this please write me, I wanna know if this was real or just a dream. I've never done it again after that.
There is a difference between Astral Projection and Out of Body Experience. What you are describing seems more like OBE to me. AP is something that occurs through concentrated efforts and is a controlled action. OBEs can happen randomly like what you describe.