Positive opk same cycle day every month

[pamg]

Just wondered if anyone gets a positive opk the same cycle day every month? I've been testing for 12 cycles now & I get a definite positive on CD15 every month but my luteal phase changes & is between 9-12 days.
When I looked around online it seems most people have the opposite that they don't always ovulate the same day each month but their luteal phase is the same!

 

[Flueky88]

O can vary due to stress, illness, hormone issues. Luteal phase is only a day or two difference. A 9 day luteal phase can be an issue as you may still be trying to implant. My luteal phase was 11 or 12 days after dd. I think once it was 10 but I think it was me regulating pp. I O usually cd 18 or 19.

When ttc my first I had irregular cycles so O really varied, but my lp was 13 to 15 days.