Corpus luteum defect

Hi everyone! So we have been trying for about two yrs and have had no success. Today I went the the fertility dr. Right off the bat he told me the reason for my spotting a week before my period. I have seen many drs and have had many u/s over the last 20yrs and no one has ever been able to tell me why I spot a week before my period!!!! I’ve even googled it a million times!! He said it’s a corpus luteum defect. Has anyone else been diagnosed with this and what did you do? I still have to do all the u/s and bldwork but I’m hopping this can give me some easy answers.