Past 3 days have had lower left mild localized gum pain, feels like tiny scratch. Noticed 2day theres a dime bump. I floss & brush teeth every day.?

Gum pain. See your Dentist to determine if "scratch" is truly a scratch, a burn, a localized bacterial or virus infection, etc. Once cause determined, appropriate treatment can be provided. Call your Dentist to schedule an examination.
The bump is. The bump is most likely a gum infection, which would require an antibiotic and definitive treatment. See your dentist asap for a proper diagnosis and appropriate treatment. .