Clomid for irregular cycles

My husband and I have been ttc for about 8 months without luck so far. My periods have been super irregular since I got off the pill, with cycles anywhere from 5-12 weeks. My ob recently tested my progesterone level on day 21 of my cycle and (to little surprise to me) it showed I hadn't ovulated yet. So I guess I'm either not ovulating or ovulating really irregularly. Now my ob wants to discuss the possibility of trying clomid to regulate my ovulation. 
Has anyone been in a similar situation and tried taking clomid? How did it go?
Thanks!