I have a small, red, painless bump on the inside of my mouth. it's above the bite line so i couldn't have bitten there. should i see my dentist?

YES!: How long have you had it? Does it shrink/swell? Mouth sores that cause pain are benign most of the time, like canker sores. Painless ones should be seen by a dentist who can do an oral cancer screening, or an oral surgeon, who can do a biopsy if necessary. The image is a canker sore.

Red lesion oral: If this bump is trauma, from biting your tissue then it should resolve on its own in a couple of days, unless you keep biting the same area. Rule of thumb for all lesions is to see a doctor if it persists, or worsens. It is never disapointing to tell a patient "its nothing to worry about now", rather then the patient not give me a chance to see it before its gotten worse. Good luck.