Precaution is better than cure??? NO! Cure is better. You may want to see a doctor though, it could be migraines, blood clots, or the first warning signs of a tumor. Many things cause headaches, only a physical examination can tell what is causing yours.
Migraines can last up to 72 hours but that is not common. You should speak with your doctor. Have you seen any auras? or your vision became blurry? Because that is a sure sign that you are having a migraine.