When I was younger, I had scanty periods but now that am a total full grown adult, I can say that it’s more than scanty. I have steady big flow periods. Those times when I have light ones, I was not alarmed about it nor worried about it. But there are some who does panic. They think that something bad may be going on. According to Dr. David Soper, a professor of gynecology at the Medical University of South Carolina in Charleston, don’t panic if you have shorter and scantier periods because it is not always a sign of trouble. Further he said that the following can be common causes:

- Birth control pills. The hormone progesterone thins your uterine lining, so there’s less tissue buildup and less blood to shed.

- Thyroid conditions may be the cause if you have other symptoms like excessive fatigue and weight loss or gain. You should get a blood test to check your thyroid hormone levels.

- Stress. Stress suppresses estrogen, causing light short periods. Cut your stress and wait three months if your normal flow returns. If not, see your doctor to rule out pregnancy, a benign pituitary tumor, perimenopause, or in rare cases, endometrial cancer.

source: redbookmag.