Body jerking every so often but couldn't project

So last night I used a sleeping induction audio (which I hardly ever use) and noticed that I was in a relaxed state and was ready to fall asleep soon. I kept repeating mentally "I made it". Insisting that I was already astral projecting. I noticed I was emotionally in the state of it being true. I had no sense of doubt.

However for multiple times, I noticed suddenly my belly dropping and a loud exhalation through my nose at the same time every so often. I'd say it happened maybe about 5 or more times in different minutes.

It sorta reminded me of when you're on the edge of sleeping and you catch a part of your body jerking. But I found this strange because I would assume different parts of your body would suddenly jerk if you were on the edge of sleeping like maybe first the foot, then the hand, and then the leg and so on. But it was the very same sensation of belly dropping and an exhalation.

What was happening? Was I on the edge of sleeping every time my belly dropped or something else? I know the astral body never literally leaves the physical body but it sorta reminded me that my astral self was "activating" itself to project from the body but still needed practice?

Or maybe I was just super close to projecting but my body kept on waking up?