I've been there and done that - really intense headaches when I cum, from what I've told its usually something to do with the blood vessels in the brain contracting as you orgasm. Once I got more used to sex with my G/F they stopped, but if they are worrying you there's nothing wrong with getting professonal help

__________________
What is life?
If not an excuse for death,
and what is death,
if not an escape from life?