How To Stop Heavy Vaginal Bleeding?

My doctor told me to take duphaston to stop my heavy bleeding (due to endometriosis) during this monthly cycle. Last night, I accidentally took double dose duphaston and my bleeding came on again heavy which I am afraid it will not stop.. Can you tell me how to stop my heavy bleeding? And if I continue taking duphaston? I have 4 more days to complete my doctor s prescription. Thanks.