It all depends on the type of headace you have and where exactly it hurts.
~A typical migraine headache lasts less than 24 hours. Less commonly, a migraine can be as brief as 20 minutes or last for weeks.
~Tension-type headache can persist for days, weeks, or sometimes years.
~Cluster headaches are very intense but brief, usually lasting 30-90 minutes and repeating two to six times a day during a cluster episode.
Just make sure to see a neurologist, knowing from experience and having bad headaches and migraines a neurologist really helps.
Hope this helps!! :D
