I accidentally scratched off a mole, and it didn't bleed underneath. the skin underneath is just a little red, and i'm worried about scarring?

It may: I would keep the area clean and provide a clear cover with an antibiotic ointment or cream. Any disruption of the skin surface can trigger a scar formation but the intensity of scarring is less if any surface infection is prevented. It should seal over in a week or so but may take 6-8 weeks to reveal what its appearance will be.

Agree with Dr. F: Once it heals, leave it alone. If the mole doubles in size, becomes irregular in size, shape or color, bleeds, ulcerates or develops a nodule, see a doctor. Wish you good health!