Recently, I've been meditating for consecutive days now. Cause before I'd only do it for once or twice a week. Well, lately I've been noticing that after I've reached this relaxed state, I notice this "presence" of some sort in the room. I can't see it but if I concentrate on it, I tend to see these wavy/transparent/barely visible movements (though I can't see any form). And I've been having this tension of fear and excitement when I'm in the room.
Is this just imagination or something else?