I'm 16 and I first got my period at the age of 12 but it's always been irregular I went without it for 2 years before. And now it's been 6 months but I get the cramps like really bad just I don't bleed and they get so bad it's where I can't walk at all and idk what is wrong. I'm not sexually active. I'm not on birth control or anything it's just like that..