What causes tingling sensations in your teeth and gums. I've had X-ray and there nothing wrong. I have sensitive teeth?

Gum disease. The bacteria and other particles, constantly form a sticky, colorless toxic “plaque” on teeth causing the gums to become inflamed, painful, numb ( tingling sensations) and easily bleed. This is a serious health problem, called gum disease (gingivitis) which should be checked and treated by a dentist. Call your dentist ASAP.
Allergies? It could be allergy or sensitivity to foods, liquids, etc. Your own dentist and\or physician would be the ones most likely to help you determine the cause. Pay attention to when it tends to occur and if it is related to what you are eating, drinking, doing.