Talk to people you trust or go online to find a good dentist. Referrals from friends or families will ensure you can trust your experience. Because you are not likely to be qualified to determine if you indeed have a cavity, you will need a dentist to do this. Make sure you get it checked out so as to avoid more damage to your teeth. This will help them to focus on those spots. If the cause of your worry or discomfort is not a cavity, the dentist may still be able to help. Try to be as specific as you can be and explain when and how you feel the pain. Let your dentist know if your feel sharp pain while they are examining your teeth. This physical probing of your teeth will enable the dentist to tell if you have a cavity. They will poke and prod in different locations to test the strength and damage at any spot. Make sure your dentist does a thorough examination on any tooth that gives you problems. This may reveal cavities or other issues. When cavities form between your teeth, it is not always easy to tell they are there. In these situations, a dentist cannot probe with a dental tool. They will not fit between your teeth. In this case, a dentist can take an x-ray to reveal the presence of any cavities. If you feel that you have a cavity, you may wish to have your dentist take an x-ray to find out the extent of the damage.

Summary:
Find a dentist. Tell your dentist about the problem area. Get your teeth probed. Have an x-ray taken.