What Causes Severe Stomach Aches During Periods?

hi i am vinita mane,m 22 years old,i have severe stomachache during my menses also i suffer from loosemotions&vomiting on my first day of my menses & severe backache, i am having this problem for nearly 8 years ,everytime i have to take painkillers for it & sit at home the first two days also my periods are regular.do i need to do USG?please help