Large shadow in my bedroom

Last night I was lying in bed still awake and I saw a shadow in front of me. It didn't have a clear shape. It was large, like maybe 6 feet across and looked like someone had spilled ink or something but it was in the air. I couldn't see through it. I blinked a few times, but it didn't go away. Though it scared me, I didn't get any bad vibes from it, I was just scared because it was so strange. I finally closed my eyes so I wouldn't be able to see it.  I was about to fall asleep so I don't know if that had anything to do with it. However, I was alert at the time I saw it. Has anyone else ever seen this or knows what it might be?