This cycle I did letrozole 2.5mg cd 3-7 and then estradiol cd 8-12. Then will start progesterone. Does letrozole/estradiol combo cause you to ovulate early? I typically get my peak cd14, however I got my peak today cd12. Are OPKs reliable when on these meds? I got 2 clearblue advance peaks. One I had been doing, the second was a newly opened reader it went peak immediately.