The Strangest Experience

I just had the most bizarre experience that made the hair on my neck and arms stand completely on end ! While I was playing with our Chihuahua, our usual playtime in the morning... and once play has started for our little dog she is focused on nothing else... but attacking my hand under the blanket ! All of a sudden she froze and turned on a dime to look towards the bathroom door... I have never seen her with full teeth bared and all her hair standing up, she was barking like her life depended on it. Now she can't jump onto my bed, it's simply to high for her, but as she was barking at the door she was backing up to the point she was about to fall off the bed ! her gaze was focused on the door and then she slowly followed what ever she was seeing to the corner of the room, then slightly upwards and back to the bathroom door... I grabbed her, still barking and placed her on the floor... never once taking her eyes off the bathroom door, but backing herself out of the bedroom... I'm staring at the same area of the room she is and I see nothing ! But alarm bells for me personally are going off ! I just made the statement out loud " Go Away Now ! " said a quick prayer, grabbed my dog and got the hell out of the bedroom ! the two of us ran straight into my eldest son who was shaken by the way the two of us were looking and went into the bathroom... he said it was really cold in there ( even though the heater had been on the rest of the house was still warm) needless to say it creeped him out and the three of us hung out in the livingroom until my husband got home... maybe it was nothing, then again maybe it wasn't... it was just creepy as all hell...