No ovulation while on clomid!?

This might get lengthy but...I am on 50mg clomid, just started it my last cycle. I have PCOS and have been on 1000mg metformin for over a year. The met has my testosterone levels in check now. In 6 months I've ovulated 2 times (May and July) I started my clomid for my August cycle and didn't ovulate? Is this normal? My dr said upping my dose isn't an option until after 5 months and further testing. Is this normal for first round of clomid? I tested from day 9 to day 20 of my cycle.