Few months ago I noticed a new tiny mole (1 mm) in the skin folds beside the armpit, and it did not change color, shape or size. It's brown, a little raised (it feels actually as a skin tag), regular borders and color, symmetrical, so it looks just fine, but unfortunately I have health anxiety and anything new on my skin concerns me. I am in my mid-30's, Caucasian, medium complexion and have skin check every year! Is it common to get new moles as we age? Do I have reasons to be concerned? Thanks.