Thank you for your question. It appears that your periods have become scantier over the past few months and you have also missed a period. It is not unusual for periods to change like this if you are going through a significant life event such as weight gain or loss, moving home, starting a new job or college or moving house. If not it is probably best to see your gynaecologist for some tests to rule out any significant  problems. Keep a menstrual calendar so that you have a clear visual picture to show your doctor. Best wishes