I concur with Pum to have it checked out.
I would try not to be overly excited until you've had it biopsied or treated.
What people do not realize is that there are more anomolies to the skin than cancer (i.e. Actinic Keratosis, Seborrheic Keratosis, Lentigos, Nevi...) and until you get it looked at don't let your head rule your emotions... However, get it looked at.
Please see your doctor about this. It's hard to say over the internet and needs to be seen especially as it has been changing. Take care.