It’s common to have irregular periods during the first year or two (after you start your period), but after that your periods should become more predictable. Irregular periods can be caused from your hormones not being in balance, from low weight, being super physically active, pregnancy, and different kinds of medicine can also affect your menstrual cycles. Talk to your health care provider and be sure to tell him/her about all of the medicines you take, including over-the-counter herbs, diet pills, and birth control pills.
Our health guides are developed through a systematic, rigorous process to ensure accuracy, reliability, and trustworthiness. Written and reviewed by experienced healthcare clinicians from Boston Children's Hospital, a Harvard Medical School teaching hospital and consistently ranked as a top hospital by Newsweek and U.S. News & World Report, these guides combine clinical expertise, specialized knowledge, and evidence-based medicine. We also incorporate research and best practices from authoritative sources such as the CDC, NIH, PubMed, top medical journals, and UpToDate.com. Clinical specialists and subject matter experts review and edit each guide, reinforcing our commitment to high-quality, factual, scientifically accurate health information for young people.