Chronic pelvic pain (CPP) affects a significant number of women worldwide. Internationally, people with endometriosis report significant negative impact across many areas of their life. We aimed to use an online survey using the EndoCost tool to determine if there was any difference in the impact of CPP in those with vs. those without a confirmed diagnosis of endometriosis, and if there was any change in diagnostic delay since the introduction of clinical guidelines in 2005. 409 responses were received; 340 with a diagnosis of endometriosis and 69 with no diagnosis. People with CPP, regardless of diagnosis, reported moderate to severe dysmenorrhea and non-cyclical pelvic pain. Dyspareunia was also common. Significant negative impact was reported for social, academic, and sexual/romantic relationships in both cohorts. In the endometriosis cohort there was a mean diagnostic delay of eight years, however there was a reduction in both the diagnostic delay (p < 0.001) and number of doctors seen before diagnosis (p < 0.001) in those presenting more recently. Both endometriosis and CPP have significant negative impact. Whilst there is a decrease in the time to diagnosis, there is an urgent need for improved treatment options and support for women with the disease once the diagnosis is made.