How To Treat Menstrual Irregularity?

i am keen on conceiving my all reports were normal then my doc told me to take clomid and duphaston.for 1 month i took but it was painful next month i did'nt .now i have missed my periods its 4 days above and then i took pregnancy test on 4th day of my missed period but its negative.my cycle is of 35 days.i m confuse that whether these pills cause delay in periods or i took early pregnancy test.my age is 27,height 5.7,weight 62 kgs