Is positive opk but no ovulation common?

R

I got a positive opk yesterday, and peak today. Lots of ewcm yesterday and this morning. I know it’s possible to get an lh surge but not actually ovulate, even though it’s uncommon.

So my question is HOW uncommon? Like 2% of any given cycles uncommon? Or like 30% uncommon?

This is my first time having a positive opk and signs of ovulation since starting metformin so I’m a bit nervous!