Should I get a gardasil vaccination?

They are free and apparently prevent cervical cancer... but there havent been any studies done on long term affects. My doctor says its safe and i should get it but im concerned its going to be an epidemic in 25 years time. My doctor also told me to be aware that its an extremely painful injection (almost as bad as bone marrow apparently says someone i know who has had both) and 1/4 girls faint within 25 minutes. But if it prevents cancer is it worth it?