After eating chocolate i feel some pain in my teeth what does this means?

Decay: It's possible you have some decay. Also, i you may have hypo- calcified areas in your teeth which can cause sensitivity. A dental exam would help. You may need fillings. You may need something to help with the sensitivity, such as mi paste.

Cavities?: Sensitivity to sweet most likely indicates one or more teeth with a cavity, broken or deteriorating filling or perhaps cervical or occlusal erosion of the teeth. See your dentist to see what it is in your case.

Decay probably: Sugar will irritate the tooth if you have a leaky filling frank decay or even sometimes root sensitivity... I strongly encourage you to get in to see a dentist before you lose a tooth or teeth and have worsening symptoms chuck.