Continue clomid or iui? Your thoughts?

 I'm 22 years old, been ttc for a year and a half diagnosed with mild pcos. I have 50 day cycles, but they are pretty regular .  did 5 cycles of clomid, ovulated on 4 cycles at 100mg but still not pregnant. I'm so confused at this point on what to do. I've read that the lifetime limit to clomid is 6 cycles. I'm starting to feel that clomid isn't ganna work (i understand that clomid did what its supposed to do though). I talked to my dr and he said since i respond so well to clomid that he wants to do a few more cycles before moving to iui. I'm just scared of doing more cycles.