Shunts can get clogged up and stop working resulting in increased intracranial pressure. This may or may not show up on a CT and may require a lumbar puncture to measure the pressure. It’s essential to see your physician ASAP to assess the situation. I hope this has already been done. Other signs of increased intracranial, pressure are visual disturbances, nausea and vomiting. I hope the cause of your headaches is something else, simpler to treat.