Good luck and get in to your dentist right away as the symptoms can become much worse very quickly!
Brett E. Gilbert, D.D.S.
Signs or symptoms of a cavity include sensitivity to cold, upon flossing, it shreds. If cavity is deep, throbbing pain, sensitivity to hot and cold, pain keeping you up night. Sensitivity can also be due to gum recession, grinding etc... cavities can be between your teeth and visible to the naked eye. I would recommend seeing your dentist. Hope this helps.
Is the tooth sensitive to temperature, is it dull or severe, is it spontaneous (hurts all the time), does it hurt when you are eating? Drinking? What temperature: hot or cold? Does it hurt more at night? When did it started? Did it happen in the past? Is the tooth moving? Does the tooth have a filling and what kind of filling (metal vs. white)? How did it start? Did you have any recent extraction? Do you suffer from TMJ? And then follow-up questions. Find an experienced dentist that takes time to speak to you. A correct diagnosis by an expert dentist is worth every penny. Misdiagnosis can cost much more than a pay out of pocket consultation exam. I know I did not give you a definite answer, but there are many reasons for tooth pain and a cavity is only one of them.
Best of luck.