If you have missed your period for six months, it's possible that it's menopause, but there are other possibilities too. I'd make an appointment with your doctor just to talk things through- they will be helpful in guiding you through menopause if that's what is happening and if there is something else going on causing your periods to be that late- they can diagnose you and assist you. I'd be willing to bet it's probably menopause, but always best to see a doctor.