Two embryo failure is actually something to be worried about. But that’s what happened when you are stuck in the middle of unexplained infertility. Nothing gets the answer. Not even the failures. And I guess that’s the reason that even doctor fails to answer to your failure. Though you may be right about switching doctor. That may help you out. That’s correct that each one should have the answer to their failures so they should know whats going wrong. I don’t know about many but I read the post earlier that says there was no reason found to her IVF failure. So yeah maybe its nothing but unexplained infertility.