Losing the syllable

So, I have been meditating since January of this year, and in the past month I have noticed that I don't actually need to think the syllable at all at the start of meditation for stess release to begin. Basically as soon as I sit down my body goes into "meditation mode" and I can feel stress being released from my body. This happens for the entire time I am meditating even though I never actually think the syllable. It also means that there is no real rest time at the end of meditation, for I have no way to signal to my body that the meditation session is over. Should I be concerned about this, or is there something I should do differently? Any advice would be much appreciated!