Olivia,
This is not uncommon. There are so many contributing factors at play.
IE: Severity of the seizure, location of the brain where the seizure activity occurred, frequency of the seizures, stress, etc.
Everybody reacts differently to seizures.
IMO ~ speak to your Doctor about this, he may have to adjust you meds or maybe send you for some further testing to determine if it could be from some other oulying medical condition.
Randy