Many young people masturbate to learn about their body, explore what they find sexually satisfying, and even relieve stress. This it totally normal! However, masturbating cannot cause you to have your period, and cannot change your hormones. It is common for young women to experience irregular periods, especially if you just started getting your period recently. Sometimes girls will experience mild irritation from masturbating but it should not cause bleeding. The best plan is to make an appointment with your health care provider (HCP).