Period question painful?

ok so i started my period this sumer and this will be my fourth period, my friend started at the same time. she has no pain no weight gain no anything and she can count thrity days and start around that time. but on my case i am having the worst period i have ever had i blead so heavily last time i had to go to the doctor because i was bleeding so much and this is the first full day of my period and i am already bleeding more than i did last time and it can only get worse. the pain is in my ovaries all the way through to my back and hips and it is unbearable in cl i was doubled over my desk trying not to cry. and they are so irragular. so why is mine so painfull and hers isnt. i am so bloated i gained five pounds and couldnt fit in my jeans this morning.