Endometrial scratch/biopsy

Dfll

So I just had my first FET and it failed:/ my RE wants to make sure my lining doesn’t have inflammation and I’ve also been reading a lot about endometritis. I have no reason to think I would have this but since I’ve gotten pregnant before we need to figure out why it didn’t implant. I’m wondering if anyone has done this before their cycle and if it worked. My RE also gave me the option to just do the scratch without the biopsy so I wouldn’t have to delay my cycle. I’m still waiting to get my period but I would also think getting my period and shedding my lining would help if there was inflammation? Any feedback appreciated. Just trying to wrap my head around what to do next.