Niki, I am not a doctor, however, I've lived with dissociation for over 60 years. When you do something and you don't remember doing it, that is a form of dissociation. That's doesn't mean you have multiple personalities, it just means you had a momentary brain fart (my term, not in medical dictionary). It's not really a big deal. It just is what it is.When other people tell you that you did something, use wisdom. Not everyone is on your side. They tend to think it's funny. But the reality is, when you dissociate it is not funny.
Now if you lose large tracks of time and do all sorts of things during that time frame, you need to find out what your overstress is and strive to relieve it. Stress can do strange things to people with PTSD as well as those who don't. I hope I didn't alarm you.