Doppelgangers

I've had an unhealthy amount of doppelganger experiences, specifically of me and my family members.
     The first time was my mom and brother had gone to the store. I was maybe 12 or 13 staying home with my sister who is a year younger than me. Before heading off my mom calls to my sister from the open door to ask if she wanted anything from the store so my sister goes to tell her. Apparently she saw me behind my mom and brother outside. my sister just thought i got ready real quick and followed them even though i was in bed and still in my pjs moments before. a few minutes later she goes to my room and gasps because i was there, even though she just saw me in a completely different outfit outside with my mom and brother. After they came back we asked them about it and said they were alone the whole time, so the possibility of her mistaking someone else for me is out of the question.
     I wanna know if anyone else has experienced something similar? I've heard of "mimics" which are basically shape shifters from what i understand, but they are found near the Appalachia, and i live in southern california lol. Im also not near and woods. I have a couple more stories but i didn't wanna make this too long, lmk if u wanna hear them!!