Q for the dental minded

Does increased cold sensitivity of a tooth indicate probable cavity? I do have a filling on the tooth that is bothering me (and which always transmits any direct cold pain) but lately even slightly lower than room temp is bothering it - as in, sharp pain that can easily morph into very very long periods of pain if it deigns things too cold. Been like this for over a week since it got annoyed at some too cold feta.

I have absolutely no experience at this since all my previous cavities have been completely painless and only filled at the extreme insistence of dentist.