I had knee surgery 10 days ago. A few days later I had sex. As sex progressed I could feel a headache buld up. I thought nothing of it until I had an orgasm which brought on an explosive headache. The intensity of it lasted about 3-4 minutes, but the lingering headache lasted until I went to sleep. Since then I have tried 3 more times to have sex but I can feel the "build up" so I didnt bother to try and orgasm. This did not happen before my surgery. Could my surgery have brought this on? Or is this something that will pass?