The pain resembling a stab from an icepick, nail, or needle and typically lasting from a fraction of a second to 1 to 2 seconds, is a headache with the shortest duration of all known headaches, described as idiopathic (without known cause) stabbing headache.
It appears always at the same spot, and, usually one sided.
The brief, sharp, severe jabbing pains can occur either as single episodes or as brief repeated volleys with irregular frequency ranging from 1 to many per day.

Have you noticed some other symptoms like painful eye movements or vision loss?

If dont get any joy from the last answer , another suggestion could be a sign of something rare i suffer called cluster headaches, look that up to and see if any other symptoms match? good luck!