Hi, I m 15 years old. I got my period when I was 13. My menstrual cycle never been normal. When I have my period on the 3rd day of the period, I always get really bad cramps ad when I use ibrueprofen or pain relievers and they never work. But I ll always get shaky,weak , sometimes vomit , and lightheaded. And I don t usually finish my food. I go to the nurse and she says I have low blood sugar and I have low iron too. I used to faint in 8th grade and when I m on my period. My eyes go black and I just go black wherever I am. An then I open my eyes and I never remember what I was doing seconds before it happen. I just want to know is this normal. And I always have a low blood sugar but it sometimes goes back normal.