Really bad period cramps!!!

Im 18. I had my first period when i was 13 and i never had a normal period. I meant I always get period cramps. When I was 15, I frequently had a really bad period cramps and sometimes i even collapsed!! Most of my friends said that it was normal. And till now, Im already used to it. But few days ago I heard that sometimes if people get a really bad period cramps they might have cyst or cancer. Whats ur opinion?? Maybe u have any experience??