Are There Any Side Effects Of Taking Duphaston To Regularize Menstrual Cycle?

I had a laparascopy done for endometriosis in Oct,got 3 zoladex injections since then,my last was in December...I have been put on duphaston to bring my menses back and help me get pregnant as i will also get clomid from day 2 of my menses..cab duphaston fail to bring back my menses and if so what can i take?