There are all different guidelines for judging whether or not a mole is reason for concern.
Is it jagged, wavy or irregular shaped?
Is it a solid color or a mixture of colors? Has it crusted or bled?
Is it raised?
Is it bigger than the size of an eraser?
If you answered yes to any of these questions you may need to see a doctor or dermatologist.
(Be sure you're not confusing any skin tag moles with cancerous moles. Skin tags are raised, narrow growths that are harmless.)

I would suggest that you have your doctor take a look especially it is bumpy (you can feel it) and because it has enlarged. Just to be safe.

Moles that turn into cancerous melonoma are usually there from years ago...It is the changing color of them and possibly the bubbling affect that they take on that is an early indication of what is happening....I have a child that has had many of these removed....

If you have any questions go onto the google site and take a look at some of them....I would doubt very seriously that what you speak about is this type of mole....As we age we sometimes grow moles.....

Check with a Dermatologist if you are worried, but first check the site.....

Caroline