Is It Normal To Have Light Periods And Spotting After Taking Duphaston For Three Weeks?

i was suggested by doctor to take duphaston 10mg for 21 days twice a day, i got my period after 4 days of stopping duphaston, the periods are very light and i started getting a very light spotting 2 days before my period started, i just wanted to know if thats normal, because my previous cycle was very disturbed i got light periods for almost 15 days straight