Yes, it is possible to have DID and not know it... I was not Dx with DID until I had a mental breakdown at age 30 (i am 42 now) and from what my therapist and I came up with I was probably aware that some thing was different with me around age 12 - I just didn't know what.

Seeing a professional that can correctly Dx you is the way to go here, but feel free to share and ask question in the mean time... ((( hugs )))