Endometrial function test - anyone had it done?

[mizuno]

My FS suggested I do endometrial function test, which is basically endometrial biopsy where they look to see if everything is ok with your lining (I'm in Canada, but the sample will be sent to Yale). I do have a pretty thin lining, so I can see why the doc would order it, but it seems that it's a bit controversial as in how useful it is. She wants me to do this before going through with IVF.

Has anyone had it done? What's the protocol before the biopsy? Are there any dangers? What can it tell them that would change my IVF protocol?
It seems to me that poking at my already thin lining may not be a good idea . Plus, it will be a wasted cycle, which I also don't like.

Thanks!!!