So.. I built a nether portal to the nether, I encountered a lots of Ghast, what happened is, when I was hit, almost died, I went to the portal again to return because I was about to die, then a Ghast shot a fire charge at me & at the exact time, when the screen showed 'Building terrain' I heard the explosion of the fire charge at the exact time, so I moved & I was stuck, I was like "Wait what?! There are no walls behind the portal!" Then I moved sidewards & saw a new portal appeared to the side of my original portal (Portal with the cobblestone frame) & I was shocked when I saw two portals.