Every woman with endometriosis has an origin story, a memory of the first time she knew the pain in her pelvis could not be normal. For Emma, it goes back to the day in 10th-grade history class when she blacked out. The sensation, she says, was how a pumpkin might feel when its insides are scraped. Her gynecologist assumed she was having bad period cramps and gave her birth-control pills. They helped but not enough. “He made me feel as if I were acting a little crazy,” says Emma, now in her late 30s, who asked to go by a pseudonym. “It struck me much later that when a woman's medical problem isn’t clear-cut, she just isn’t believed.”