Higher dose = stopped ovulating ??

As

I ovulate on my own with unexplained fertility so my doc prescribed Femara (unmonitored).

The first 3 cycles (on 2.5mg) , my periods were like normal (on time) and it seemed like I was still ovulating based on opk.

4th cycle doc upped it to 5mg and I had an anovulatory cycle by my guess. No positive opk and my period showed up after a 21 day cycle which has never happened before !

This month, Upped to 7.5mg and it looks like a repeat of last month - no positive OPKs. Not even close. Stark white.

I Can’t get in to see my doc for a couple weeks but wondering if anyone has experienced this?