I think if the skin doctor told you your mole was a benign non-cancerous unnas naevus you can be certain that is exactly what it is.  If the doctor was in any doubt he would have taken a biopsy so to give you that diagnosis without biopsy is a positive outcome for you.  

A few years ago my GP told me I “probably had” a BCC skin cancer but sent me to a skin doctor “just to confirm”.  She looked at it once & told me it was definitely not a BCC skin cancer but sebaceous hyperplasia- a harmless non-cancerous skin lesion.  We have to remember that the skin doctors are the experts- they are looking at skin conditions all day, every day & will know just by sight if something looks to be of enough concern to warrant a biopsy. We were both lucky to have been diagnosed with a non-cancerous condition by people who are experts in their field. Nothing you will have said would have stopped the doctor taking a biopsy if he felt it was likely to be something of concern.  Don’t worry- you’ve been given a good outcome by an expert.  Take care.