cigar like encounter

It was a early morning, i was up on my bed looking out the windows waiting for my friend call to go to work.  while i was looking out the windows i noticed this cigar like between the two buildings, at first i tought it was helicopter but it wasnt moving at all and it looked more like submarine, i didnt think of anything weird until this thing moved forward to one of the building and then back, at that movent i didnt know what to think or say. this thing the moved up and forward again. i went to the kichen to see if this thing whatever it was. I couldnt see it anywere it was gone. up to this day i think that if it was a plane or chaper i would of been able to see.  that windows has a clear view to the mentionned area.
Date is approximate.  PD