What's best to regularize my period as its always late. is it duphaston or primolut n? considering taking 1x3 pills/day. i'm 33 days late & not pregnt

Depends: While the progesterones you mention can cause a withdrawal bleed, it may be that you don't have any lining to bleed from. Have you talked to your doctor about birth control? Typical birth control is a combo of estrogen/progesterone, which typically gives a woman a regular cycle. Consider that thyroid can also play as role, as can weight (too heavy/thin). Talk to you doctor for additional info.