Ovulation question

This is my 4th cycle ttc

Can you still have a very regular period but not ovulate every month? My period comes like clockwork, every 25 days not a day early or late.

I’ve been using the clear blue digital opks..the first month I got two days of a high reading then peak.

Second month I had nine days in a row of high only, right up until the morning of my period.

Third month I never even got a high reading.

This month so far I have had four high day, I have also started to track my bbt.

I can my period be “regular” and still not ovulate for multiple months?