I guess i'm having a similar experience.
Sometimes, when i wake up early in the morning, i get back to sleep, but i do not try to induce entering dreams. I just try to sleep. Then, i feel extremely relaxed and my body enters sleep, like normal. Until now, i just entered the dream, not feeling my body relaxing. But now, before entering a dream, i'm aware of my body relaxing and vibrating.
Today, i was trying to go back to sleep. I then felt my body heavier and vibrating. I heard also a buzz sound. I then concentrated on what my eyes were showing. I saw some coloured circles, kinda like atoms. Then an image of a newspaper's headline. All in a black background. It lasted for about 3 minutes. It was weird but i liked the experience.
What name does this kind of state has?
Funny thing that happened next.
While on this state, i wanted to have an OBE. Concentrated on leaving my body but something was blocking me. Felt like the ceiling was near my body, or like i was inside a box. Then i woke up.
I then saw why i was not able to levitate. My mind thought i was lying on my back but i was lying on my belly. It was my own bed blocking me.