Sharp pain on left side of head, sometimes last for awhile. No other symptoms. On random places before, now it's on on left side. Not getting worse?

Doctor can evaluate. A doctor can evaluate headaches and offer treatment. Some medicines are "preventive", and others stop pain after a headache starts. Headaches are very common, and have many causes. Some are migraines and others are tension headaches. Emergencies include: having a "worst headache ever", a headache that gets worse and worse as the day goes on, a headache accompanied by other major symptoms, etc...