What is making me teleport instead of die?

So, I'm playing Afterbirth and twice in a row on the same floor (once at Krampus and once in a random room) I have been teleported to a different room on taking fatal damage. I looked up all my items and I have no idea what's causing this.

I have: x-ray vision, large odd mush, box of stuff, mom's perfume, lunch, boom, and my trinket is host hat.

As I read your question I noticed that you said your trinket was "Host Hat", which is actually an item. What you probably were holding was the "Cursed Skull" trinket, which teleports you to another room if you are damaged to half a red heart.