Can Duphadton Be The Reason For Delay In The Periods?

hello doc, i am 29 yrs old female having ht of 5ft 6 inch with 70 kg wt,
5 months back i had a missed abortion, d&c was done and biopsy report suggested partial hydiatiform mole, after that my all 3 consecutive B- hcg test was neg. sonography suggested no ovarian cysts.
2 month before my doc advised to do thyroid and s. vit b12 test, thyroid was normal my s.vit b12 level was low (doc also suggested me to take tab duphaston 10 mg twice in a day for conceiving from 21st day of my cycle, today is the 35 day of my cycle, till i didn't get menstrual period n my preg test is negative. this is my first cycle with tab duphaston.
*normally my period is very regular on 28th day.
* is duphaston cause delayed menstruation? i am still taking duphaston tab should i stop it?