Hi,
Having periods that are very frequent (every 2 weeks) and having periods that don't occur (skipped or delayed) are considered 'irregular' periods. Excessively frequent periods (periods that continuously appear every 2 weeks) should be looked at more closely by a doctor because they could be a sign of hormonal imbalance or another health issue. My suggestion would be to start keeping track of your menstrual cycles on a calendar or in a journal. You should make note of when they occur, how long they last, any spotting or bleeding between periods, light or heavy flow, any pain, and anything that seems unusual. If you're periods continue to cause you concern, you should speak with your doctor. During your appointment allow the doctor to view the notes you've been keeping on your menstrual cycles; this will help the doctor have a better understanding of what is going on with your periods. Good Luck :)