I'll do my best to help you understand. Just bear with me because I may use wierd analogies to help.What kind of pain it is, where you feel it, if it happens some times of the month more than others, does it get worse when you move or do certain activities, etc. I am interested to hear this from anyone who has either of these conditions because I'd like to understand how it affects your daily lifestyle in ways that a medical article wouldn't cover.
All of my pain (usually) is during menstration. It starts with a sensation similiar to a pinched nerve in my lower back, then goes down my legs. I also have pain in my lower abdomen that, when I described it to my male buddies, immediately said that it was similar to being kicked in the nuts.
If it's going to be a bad month, I will begin to get nauseous and see spots. I usually bleed so badly I must wear an adult diaper or risk looking like a murder victim (and to save my poor sheets). This means I must take iron pills while this is going on to prevent my iron from getting too low.
Sometimes activity helps, usually in pacing. So sometimes I will pace for hours. Also, a temperature below 78 degrees makes the cramping much worse.
Oddly enough, I also cramp during ovulation. Similar symptoms as described, only much more mild.