What Causes Delay In Periods And Conception?

hi i m 33 years old and trying for baby almost 3 years. i have taken 3 cycles of clomid but unsuccessful. i have done hsg in march before ovulation and after period but no blockage. i will ovulate during day 15 but i have bleeding like period but not so heavy but until now in april my period is late 4 days. is it normal.