Sleepwalking???

Urgh...had the worst experience ever this morning....At around 6am, I got up from bed, walked out of the room and subconsciously locked the door without bringing along my room key, walked to the toilet and.....by the time I was fully conscious I was knocking on my room door and fumbling with the doorknob....BUT the whole process ever since I got down from my bed I was totally half conscious only...no idea what I was doing till I suddenly realised I was knocking on my door...and the thing is...my roommate's been not back for 2weeks already!!! Okayyy....this is getting kind of creepy =S I had such experience before...but not as serious and terrifying as this....my sis is now worried that one day I'll walk without knowing out of the door and head for the balcony instead..and I stay on the 4th floor *speechless*