Thanks for the query.
Scanty flow during periods is called hypomenorrhea
It can occur in conditions like anemia, poly cystic ovarian disease
, changes in diet or exercise, stress and strain, thyroid disorders etc which can lead to hormonal fluctuation.
If there is possibility of pregnancy
we have to consider the implantation
So you once consult gynecologist and get examined to find out the actual cause and take treatment accordingly.