Painless bump on my gums behind my lower level of teeth. feels like hard tissue. doesnt hurt at all when i press on it. definitely not a sore. i do occasionally press my tongue against my bottom teeth so im hoping it could be a callus?

Mandibular Tori: From your description, you appear to have mandibular tori. They are bony protuberances. Your dentist can make a definitive diagnosis upon examination.

Bone growth: Many people have this bony growth called a tuberosity .It can occur on your palate or on the inside of your mouth in your back teeth. It is non cancerous and can be removed by minor surgery if it bothers you.

Must see Dentist: If the hard bump on your gum is located behind the Second Molar Tooth ,possibly it is Impacted wisdom tooth .If the tooth is impacted oblique or Horizontal it will not erupt on it’s own which can be determined by your Dentist if he/she takes Panorex radiograph . The Bump can also be A Torus but nothing to worry.It is only removed if becomes too large and encroaches on Tongue space