Laurensmom, DD lived like that for a long time before we conceded to trying meds to do something about it. This was a first. The pain was easily at 11, and "normal" period pain for her had been 8-ish-- which was very, very bad-- bad enough that she wanted opiates a few times, if that says anything. This was off-the-scale awful pain.
She has had hideous periods and Mittelschmertz both-- and this is the reason why her cycle is hormonally controlled at this point (in college she could no longer afford to miss 3-5 days a month to this happy horsepuckey, KWIM)--
this was definitely not either one.
But it was like menstrual cramps-- just much, much more intense, and in waves.
The only reason that I didn't take her to the ER was that we were in a hotel room, and it was at least clear that pressure on her abdomen did NOT increase the pain-- at all. It was definitely not one side or the other, either, and the location was pretty focal. Some referral to lower back.
Interestingly, heat applied made it worse-- WAY worse. I made a hot-pack for her and she tried it briefly.
I remember the exact same presentation with one of my first truly bad shrimp reactions. It was surreal how bad the pain was. Childbirth was the only thing comparable (and I say that with experience of kidney stones and diverticulitis).
Hedgie, that is really interesting. I know that there is a connection-- research has been done on some of the gender differences in asthma and atopy during adolescence as a means of explaining the apparently enhanced risk of fatality in females in that demographic.