When I dissociated really badly a few years ago, I looked and acted normal apparently, just have no memory of it. I actually was more help-seeking at the time and "woke up" in the hospital a few days later. I don't know if that helps or not, but that was my most recent experience that I am sure of. I have suspicions of at least one more time within the last few months, but no way of knowing for sure.
(Hugs) it all might be a good topic to bring up in therapy again, especially if you are worried about your child during any lost time.