@Murindi,
That's odd, head CT or MRI scans are done to find the cause and location of the problem in the brain. If your tests came out ok, then you have to go see other doctors. Usually when seizures occur more than once or over and over, it's usually a sign of epilepsy, which is a brain disorder. Seizures may occur because abnormal electrical activity in the brain and because clusters of nerve cells, or neurons, in the brain send out the wrong signals. You should also know that there are two main groups of seizures, one: focal seizure or partial seizures which happen in just one part of the brain. two: generalized seizures happen when there's abnormal activity on both side of the brain.
Not to worry you, but when a doctor prescribes medication for your seizures, he or she MUST know which type you have and since you said your CT scan came out ok, that sounds pretty freaky especially that they already prescribed medication to you without knowing exactly what you have.
Just remember that people with uncontrolled seizures should not drive. Also, you should wear some medical alert jewelry so that medical treatment can be given to you. If you have uncontrolled seizures, you should avoid activities, such as climbing to high places, biking, and swimming.
Good luck, and visit another doctor.