You have to get your examination done , before prescribing any scan like mri brain

Headaches can be vascular type for example migraine and tension type headache,where the scans may be normal. Other causes like sinusitis are also common cause for headache. Do you have any red flags ,namely headache is very severe, waking you up from sleep or you have associated severe vomiting or blurred vision or other neurological symptoms ?  Also how frequent is your headache? It is advised to Consult a Neurologist for detailed evaluation and treatment.