July 5th CT scan for headaches. It was normal. 5 days later jerks when trying to sleep. Now think I'm having brief seizures at night. No history of seizu?

Hypnagogic jerks. Our bodies sometimes jerk briefly as we are entering sleep. It may wake us. They last less than one second. They are common and not harmful. The best way to know if you are having seizures at night is to have a sleep study, but what you describe does not sound like a seizure.
Could be normal. Brief jerks whilst sleeping can be normal. .
See doctor. You will need to see your doctor or neurologist for further testing if you think that you are having seizures. There are many types of seizures and you will need testing to sort this out.
Sleep myoclonus. It is most likely you are experiencing sleep myoclonus. If you have concerns, consult a neurologist or sleep specialist.