I started my period when I was 10 years old. I had them normally until age 15. Then I suddenly quit having them for 8 months. I had to get an HPV shot for school, and one week later they came back. I went to the doctor and they took some blood tests. They said everything was normal, and since I've never had sex, they didn't do any other tests. The periods continued for two months, then quit again. It's been 5 months now, and still no period. Sometimes, I have really bad cramps like I'm menstrating, even though I'm not. I'm starting to get worried, because cancer runs in the family. I want to know what I can do.....??? %-)