When I took prometrium 3 years ago, it took about 12 or 14 days to get my period. I only had one cycle since I got pregnant with my son on the second round. Good luck!!!
I had to take prometrium to bring on a period as well. After i had my son my periods were normal for a few months and then I just stopped getting them. Dh and I wanted to start TTC #2 so my OB prescribed prometrium for me. I started to bleed 3 days after my last pill.