Short Luteal Phase After Stopping BCP

Has anyone experienced having a short luteal phase after coming off of birth control? 
My first cycle off was normal with a 12 day luteal phase (ovulated around CD 15 according to my charting). 
My second cycle off I only had a 10 day luteal phase (but ovulated around CD 15 again). 
​And now, my third cycle off, it looks like I'm starting AF today and that would give me only a 9 day luteal phase (with ovulation around CD 15 again according to charting). 
​Has anyone had this issue after coming off birth control and did it regulate itself? 
​Is there anything I can do to naturally help lengthen my LP
​I'm not sure why my first full cycle off was perfectly normal and on time and then the last two have been odd. :/