Mole on breast for 4 years. no change really but not symetrical, a little color outside border. pinky/peach in colour? health anxiety :( melanoma?

Please see a dermat: Dermatologist, the dermatologist will be able to decide if it needs to be removed or not and will send it to the lab for diagnosis, if you are worried u need to make an appt.

Unlikely but...: The fact that it hasn't changed in 4 years is reassuring but the irregular borders and color variation raise a red flag. It is worth having your pcp or a derm take a look. Especially if you have a history of burns or tanning bed use. When you say, "no change, really" do you mean no change or minor changes? Take a digital photo so in the future you can compare to see if there are any changes.