How do you get tested for endometriosis?

Keeley

Since last month... I have been having pelvic pain. Not like vaginal pain. But in the area between my belly button and pelvic bone. When it hits it's bad. Cough,laugh, sex... at times it is stabbing pain. Even hurts when I try to poop... anyone have endometriosis? Is this what it sounds like? I'm 29 and this just started. Not sure what to do. Oh and period cramps are nearly debilitating.