That does not look like any nutting stone I have found. I have not found any that the depression area or use area is an irregular shape like your specimen.
Of course, this may be a factor of the particular styles and available stone in your area.
What state are you in? What was the context this was found?
Most I have found, have been in Indiana and are made of granite or greenstone, most are very round to oval and the nutting area not as pronounced of a hole area as that which your stone has.
Many if not all of the more oval style also has use marks on the ends from being used as hammer stones.
A good majority of both round and oval have the nutting stone use wear on both sides. This may not be a large divot but wear marks.