I am getting a severe Migraine any time I am coming close to ejaculating. The other night I was with my girlfriend and as I was Ejaculating it felt like something exploded in the back of my head. The pain was so intense and lasted for over 4 hours after taking to Excedrin which normally knocks it down to bearable levels. I went to have my blood pressure checked and it came out normal. So what could be causing this pain.