Why Is Dulotin Prescribed After Child Birth?

Mam I was delivered on September 12th. After delivery I was asked to use this tablet by gynecologist. But since I m working abroad , Till December I was on breastfeeding and then I came. I had regular cycle for just 2 months and my LMP was 13th Feb. Now I didn t have my menstrual cycle yet. I was worried and just remembered about this tablet. I m not pregnant. What will be the reason. Shall I take this duolotin tab ? If so how should I take.