I have a small round legion under my tongue, ita been there for a little bit and its hard in texture. I cant tell if its cancer or benign?

Examination. There a numerous lesions in the mouth that are normal. Hard spots under the tongue could be a stone from the salivary glands. Let's find out what this spot is. Call a dentist for an examination and test to be safe. .
Oral surgeon. Any intraoral lesion should be evaluated. Preferably by an oral surgeon.