Can eating disorders such as bulimia cause period problems?

i started dieting at 13yrs because i was gaining weight. i started bulimic habits at 15, and was diagnosed with bulimia nervosa at 17 when i was finally caught. i'm almost 18 now, and still struggle with my disorder. my last periods have been really painful and make me sick (shivers, back pain, the feeling like i need to vomit) and when they come is unpredictable. my last one was two months ago so i'm late again. i'm not ually active, and i've been having periods since 12 so they should have regulated by now. is bulimia to blame or could it be something else?