MOCK CYCLE AND RETRIEVAL BEFORE TRANSFER

Hi ladies does anyone know if doing a retrieval after a mock ERA cycle will give incorrect results? I know they said mock ERA cycle results are good for up to 1yr. But because iam having issues with insurance due to them not allowing embryo banking (i had my 1st retrieval in July) I have to do mock ERA this month in September, my 2nd retrieval in October, and FET transfer in November. Atleast that's the plan. But I wanted to know would the mock ERA cycle results be accurate because I saw in another group someone mentioned that whenever you have surgery your endometrial cavity changes. And since I will have a retrieval right before I have my transfer I wonder if doing the mock ERA in September will be a waste of time as iam not sure if those results would apply anymore to my expected transfer in November. What do you thinK?