Hi,
Welcome to HCM,
You haven't mentioned the color of bleeding.
During menstrual period the color of bleeding is bright red and it contains many clots in it.
The amount of blood lost during a period ranges between 20-80 ml.
If amount of blood lost during period is less than 20 ml, it can be taken as light period.
At your age the cause can be like
stress, excessive exercise,
eating disorder,
thyroid condition,
hormonal imbalance, use of
contraceptive pills, PCOS, autoimmune disorder etc.
To establish diagnosis, thorough examination and some investigations are required.
Thus, you should consult a Gynecologist in person for examination.
Thanks for trusting Healthcaremagic and posting your query.
Hope you found my response to your query informative and helpful.
If you have further concerns in this regard, you can submit those with Healthcaremagic as well.
With good wishes,