Hi Tam
The biopsy is done between CD19 and CD25 - that's the implantation window time. It's the same legs up in the air scenario that we're all familiar with however the doctor takes a scrape of your endo lining. As NK cells are at their most prolific in the uterus during implantation time, they test it to check how many there are. Hint, pop a couple of Nurofen Plus an hour beforehand and you'll be fine I did have to clench my teeth at the time but it was only temporary 'discomfort'...
I might add, it really needs to be done by someone who specialises in the immunology area. Have you tried phoning/emailing Gavin to run any of this by him? He really is a lovely man, I don't mind you mentioning my name - he knows me well . If he can't consult for you he may be able to refer you to someone else over your way. Let me know if you want his email addy.
And yes, I can well understand the hair pulling!