multiplying mole

My body has always had some moles whiithe ones i havec havent changed iin size but i could be wrong.. My moles are now multiplying. they appeared in a very short time.

As far as color is concerned, at least one of the moles that i have always had,(fairly large)  has gotten darker with
with speck or spots on the mole that are lighter in color than the rest of the mole.that some a small part of it

The new moles are located on back, chest, and arms. These new ones vary in size and some are them are very dark with speck or spots on the mole that are lighter in color than the rest of the mole.

I am waiting for a dermatologist appointment, however i would still love some information about how and why a lot of new moles appeared very suddenly.and why the old ones ave also changed, their color has become very dark
brown.