Despite repeated statements in books to the contrary, moles on the soles are really no riskier than moles anywhere else. If your doctor thinks this one is suspicious, he is surely correct to plan a biopsy to be sure, just as he would for a mole anywhere else that looked a bit funny. Based on your description, though, the report is almost certain to be fine. If the biopsy can be moved up, that would be good for your peace of mind, but I expect you'll be fine in any case.
Best.
Dr. Rockoff