Thanks for writing in.
I read your problem,it seems that it is granuloma
or pappiloma,but you do not need to get worried,because both the conditions are self limiting.
I will suggest you leave it like that only,do not touch this again and again,it will resolve itself with in few days,if not visit to a dentist
in your area and get the thorough examination done.
As you said it is not painful and there is no sign of infection nothing to get worried.
Dr. Gunan Gupta