Today I had a peculiar sensation nearing the end of my hour of anapanasati, what I perceived as a gradual unfolding of 'enstatic' phenomenon eventually resulted in a sensation that my body was swaying in some way, though perhaps not in such a gross sense, but it felt a little like dizziness which made me a bit uneasy of if I was maintaining my equilibrium and naturally undermined some of the tranquility that I had developed. I've had other peculiar bodily sensations before and I've never placed much significance on them, and indeed that isn't my intention now, but rather those others weren't nearly so intrusive, and I raise this question because it seemed like an obstacle and one I'm not sure how to approach should it occur again. I am not sure if it was due to dullness, or poor core body strength revealing a genuine instability with the gradual falling away of the grosser features of awareness, or whatever. While I found that being mindful of the sensation reduced my feelings of disorientation, that then means that I was no longer attending to the breath. I was wondering if anyone had any suggestions as to what might be happening? My session otherwise felt like it had the directionality that samatha 'should' have, and what I mean by that is that I probably observed the process go further than I ever have before, but while many other times I've felt the beginnings of what I must assume was piti, there wasn't much of that this time at all.