No response to Femara

I have done 4 rounds of Femara now with only one round of actually responding to medication and ovulating. (1st- 2.5mg no response, 2nd- 5mg with response, 3rd- 5 mg no response, 4th- 7.5 no response) I am wondering if I should keep using opk’s to see if I still ovulate this cycle on my own or if that’s not likely to happen and just scrap the cycle and start Provera to bring on another try?

So has anyone not responded to Femara and still ovulated later on in cycle?