Allow myself to rock or sway while meditating?

I have noticed that sometimes, almost unconsciously, my body begins to sway forward and backward ever so slightly when I'm sitting in meditation (actually, kneeling - I sit zazen on a bench). It does not seem to be in phase with any of my rhythmic body functions (e.g. heartbeat, breathing). There are times when I consciously cease the swaying, but other times when I allow it to continue. Or even help it a little bit. It seems to add somewhat to the depth of my meditative state and is mildly pleasant. My question is thus: should I just let it be (after noting it)? Should I help it? Should I put a stop to it? I do not have enough familiarity with The Official Rules & Regulations Of Practicing Buddhists to know, and I do not have an instructor/advisor to pose this question to. Hence my post here. I found this related question, but this person seems to be doing it intentionally and in response to physical pain. One of the answers here also notes that it may be in response to conditioning, but I don't feel that's the case here. https://buddhism.stackexchange.com/questions/3937/a-question-about-sitting-movement-and-mindfulness