Sounds like you may be dissociating. It can be distressing having things done or doing things without realising you have done them! It is especially scary when you dont know how you have gotten home from being out or having gone shopping without remembering it. Did your pdoc bring up this suggestion when you mentioned it to him?

It can happen more in times of high stress, but I have had it happen at all times. Now I realise when it is happening and practice grounding or breathing techniques before I lose too much time. But I was losing days at one point, and it wasnt even at a stressful time!

Keep in mind it could also be your meds. I am also on geodon when I had these experiences, I am still very forgetful but I dont lose days anymore, just hours occasionally, even in times of stress (in saying that I barely remember the last 3 weeks, but that would be more down to emotional distress than the meds or dissociation).