Menstrual cramps. Menstrual cramps?

From since a year now, i've been having real bad cramps. My flow is normal, i get them almost on time every month. and a few years ago i never used to experience cramps at all. Some of my friends even at my age don't. My mother didn't not even my granny or any other woman in my house but one of my aunt has had abnormal cramps but it lasted for about 4 years then it went away. I got my xray done as prescribed by my physician if i had an ovarian cyst but the results are clear. I just want to know why do i out of all the other women face abnormal cramps when there's nothing wrong with my body as such. but yeah i've had different sorts of infections in the past like small intenstinal infection and urinal infection too. but it's been 2 years since i got recovered. Is there any relation between the infections that i've had in the past and my abnormal menstrual cramps? I'd really appreciate if you replied to my query bcos i've went to multiple doctors bt didn't ever get a solution to my prob