Had a convulsion last night, then i think i started to have another one just now. what can cause these?

Grand mal sz: If you are noting the onset of epilepsy, and experiencing a full-blown convulsion, this is not to be delayed. See an emergency room physician asap, and get brain imaging. You need a diagnosis, evaluation, and treatment. Best of outcomes. Get this fixed!

Why convulsions?: In order to find out why you are having seizures you should consult a neurologist for an evaluation.