subtle body sensations

I've been practicing feeling the sensations of my entire body in the vipassana sense, but in different circumstances - walking down the street, riding the bus etc. - not just when I'm on the meditation cushion. A couple of days ago I was lying on the couch and decided to focus that way, and what was interesting was that I seemed to sense the space around my body, with my body contained within that field. I could feel various muscular tensions and a tendency to want to contract my awareness into that, but for several minutes I was able to just relax in that field of awareness - it felt delicious. I'm wondering if I may have been sensing my "aura" or "subtle body" or what?

Lately I've been a little more prone to feeling sensations of energy flowing in my body - I've had moments of that during acupuncture or yoga, and also spontaneously in various other circumstances, usually when I have a chance to relax my focus on the external world. It seems to me that I may be developing more awareness of my subtle body. I've had occasional experiences like this for years - the first time I recall it happening was when I was practicing chi gung prior to 2001. However it seems to be becoming more frequent as time goes on and as I continue to practice various techniques.