my mole fell off

Hi,

I had a mole on my collar bone.  It didn't appear uneven, the border was not abnormal, the color did not seem strange, but one day I noticed it felt a bit itchy. -I was not sure if it was because the collar of my shirt was rubbing on it, so I started to just keep an eye on it.  About three months later, my mole seemed to scab up, i picked at it a little and a small white head came out -the kind that comes out when you pop a zit.  I left the mole alone and then a few days later, while i was taking a shower I felt it began to flap lose, when I got out of the shower it was just hanging on, I pulled the rest of it off.  

The skin below looks a bit tender.  This just happened an hour ago.  I have a band aid on it so that my shirt will not irritate it.  I saved the mole that fell off, there was a very thin dangly thing -almost like a root, hanging off the mole.  

Im sorry this is so gross.  I am wondering if I should be concerned or if this is normal?