Cat, my doctor also said no issues, and my dentist was the one to catch it. Make sure to mention your concerns to the dentist.
I'm with David ----quit smoking now! It took being diagnosed with tongue cancer at 39 for me to quit. Now I have had half my tongue removed, my neck slit open, and 14 hours of surgery to recover from, not to mention that this was just the start.
I know it's hard to quit. I had smoked since I was 14 and I was at a pack a day, and I liked it. If I can quit, so can you. Don't kid yourself that this cant happen to you.