Suspicious mole on right side of chest

Hi

Just a quick 1 really, had this mole now on the right side of my chest now for about 9 months now, 

Should I be worried that it keeps changing colour repeatedly, it is an irregular shape and sometimes flat then raised, don't really notice the size of it, just asking, I had it checked a couple of months ago and she said it's probably nothing just keep an eye on it

Just not  sure