Hello,
Following menarche, some girls have periods that last just 2 or 3 days and the amount will be 2- 3 teaspoons though it may look like much. Sometimes it may be heavy. So don't worry and wait for the next few times. If it persists then get it evaluated from a gynecologist.
It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your doctor. I sincerely hope that helps. Take care and please do keep me posted on how you are doing.