Small Luteal phase


Hi all i have 22 day period cycle. Where on 14th day i got positive opk... which means i only have 7-8 days of luteal phase... which is not good for getting pregnant know... what shld i do to lengthen the luteal phase to normal like 14 days...

Last time when we were trying doc gave me duphaston... for 14 days aftr ovulation... will duphaston make my luteal phase long ?