Hole in my Gum?

I have a strange hole on top of my tooth. I have braces and its on top of my band so I can't see what it's doing to my tooth. I had 2 bicuspid teeth pulled out. almost right after i seemed to get the hole in my gum. and it's right next to the bicuspid tooth he pulled out. It's on my gum and when I felt it, the hole seems to be deep and I accidentally went to far and it began to bleed. It's grayish in color. Please tell me what this might be an what I should do.