@julianicholson I hope your lining cooperates for you as, like you said, you've never had issues with it before.
I hope all the herbs and acupuncture and vitamins do their thing.
My last FS in Genea wasn't too fussed with my lining as he thought that was just the way I am, I have thin lining. He was telling me how he had someone who was on her second child with a lining of 4mm. He didn't put as much weight on the lining as some FS. My DD was from a lining of around 5mm.
But I can totally understand you not wanting to waste a tested egg and always wonder if it were your lining. Especially when you're used to a thicker lining. I just hope it gets a little thicker to give everyone confidence to have a go.
Wishing you all the best. Good luck! Xx