Has anyone taken clomid and success?

i finshed my 3rd cycle of clomid...at 150 mg..doc started me at 50 and worked our way up, i was getting fustrated that the meds were not working. on the 21 day of my cycle, i have to go in to have my progestrone levels checked..and well...all i was told was sorry u didnt ovulate..i wanted to give up, not to mention it was begining to get costly..then this month i got a call that said...yay u ovulated...but still not pg.....this is depressing!!!!