I feel a hard pea-sized lump on the floor of my mouth under my tongue on the right side. my dentist did not notice when palpating the area. thoughts?

Second Opinion: Lumps on the floor of the mouth that last longer than 7-10 days without healing should be checked by a dentist or oral pathologist. See an oral surgeon or oral pathologist for evaluation and opinion.

Investigation: Out of curiosity, did you notice the lump before your appointment? If so, did you mention it to your Dentist? Any pain/bleeding/swelling deserves immediate evaluation. Call your Dentist or an Oral Surgeon for evaluation. Could be one of hundreds of things, mostly benign, but should be investigated. Call now.