Hi! A couple of months ago I had a experience that i cannot understand. I was i my bed trying to sleep ( but was fully awake) and my body started to relax. It was an intense sense of relaxation, like I was melting and expanding. I started to get in tune with my breathing. I was feeling without trying, the space that my body occupies. I started to feel this intense feeling of love, in the middle of my chest, and that sensation started to expand. I was not in my bed anymore, I was not a human being I was just that feeling. It felt like I was a firework of vibrations, and it was really intense. I continued breathing and enjoying that state. After a while I felt my mind trying to analyze that sensation and it disappeared. Until today i never felt anything like that again. what was this?

Sounds very much like the Arising and Passing phenomena; the fourth among the stages of insight:
http://www.vipassanadhura.com/sixteen.html

Hi, first thank you for your answer.
Regarding the quote on your answer, could you elaborate (if you don't mind) the part where you say "having these experiences anyway, directly without anything needed,is a skill and can be practiced" ? Because i really want to practice this. This came naturally after 3 yoga classes, but I never felt anything similar to this again, just normal relaxation and somethimes "bad feelings" like purge...

Thank you! I started reading "Mastering the core teachings of the Buddha"

Sounds like a good place to start. But, make sure to stay in touch with a community like this or any other.

MCTB changed the course of my life; not unlike The Matrix. In hindsight, it would have been a less bumpy ride if I had similarly interested companions around.