Could I have Amenorrhea?

I lost 10 pounds in about 2-3 weeks from not eating, and I was supposed to get my period over a week ago but it hasn't started. My boyfriend never has food so for a while I was just smoking a lot and eating rahmen or nothing at all because I don't have much money (he doesn't mind not having food as long as he has cigarettes and soda, he eats so little food that he's literally so thin he looks someone who was in Auschwitz). I've been feeling nauseous 24/7 for a few weeks and I was wondering if I could be so sick from not eating that it stopped or postponed my menstrual cycle? I stopped smoking as well because it got to the point where even the cigarettes didn't help.