Lump on left hard palate by center ridge by jct of soft palate. teeth cleaning last week & was ok. no lesions. shuld i worry? dt would've seen it yes?

Torus: Probably a normal variant, a thickening of the bone called a Torus. If it was present at the time of your exam/cleaning, Dentist would have noted it for his/her records. No Rx is required. If it suddenly appeared since your last Dental visit it's to a Torus: call to make an appointment to have it checked.

It is normal: This is considered a normal anatomy. These lumps are naturally occurring and are benign protuberances of the bone covered by mucosa. No treatment is required.