Hard Lump on Roof of Mouth

Hello,

It seems that a lot of people have something similar to what I'm experiencing. I first noticed a bump on the roof of my mouth, hard palate, about a year ago. I had my dentist check it out, and they said it was probably a clogged saliva duct, almost like an ingrown hair. They pierced it, and said it should clear up. It's about 6 months later, and this bump is still here. Not sure what it could be. It's hard, and hurts now because I scraped at it with my fingernail. Also a bit red. I'd imagine that a type of oral cancer or tumor would have grown or spread by now, and not stayed merely a bump. Any opinions on what this might possibly be? I'm going to get it checked out anyways by an oral surgeon, just to make sure.