On clomiphene since 3 months still not conceiving. . also had a miscarriage before clomiphene what can be the reason for miscarriage n nt getting preg?

Clomiphene: Clomid/clomiphene is succesful producing pregnancies in about 50-60% of women who take it; in other words, it doesn't always work - at all. For those who succeed, around 85% do so in 3 cycles. So it's quite possible you could try a few more cycles. It also depends on normal tubes and normal sperm: have you and your husband been tested for this?