Mrs Shy - you poor thing. Big hugs from me. I have also had one fresh and one FET cycle transfer with high quality blastocysts. Single embryo transfer each time so two have been used. I have 3 blastos left in the freeze also. It is a horrible horrible feeling isn't it.
I am a similar age and supposedly healthy too.
With me, there is speculation over internal or external tubal damage. It is a long storey as I have no history of PID or endo but I am waiting for a lap to try and asses and hopefully repair any damage. This may help improve my chances at next FET.
For you, these are some of my thoughts and some questions that I would discuss with your new clinic for next FET.
Bad luck - perfect looking blasto's aren't always what they seem. Something like 30% become babies. So maybe you just haven't struck lucky yet and this is a numbers game.
Tubes - What is the reason (if any) for your fertility problems? Sometimes blocked tubes aren't spotted and there may be toxic fluid disrupting the implantation process. This is unlikely but worth ruling out.
Poor embryo trasnfer - this is what the Dr's are saying is my problem. If the cathetar irritates the cervix passing through it can cause waves through the womb and stop implantation. Both of my transfers were lengthy and special tubes used. At my lap I will also have a cervix dilation to overcome this problem.
Immunes - again not common. Could the Dr's start you on some steroids or other meds to help implantation? What tests have you had so far?
Cycle type - have you had medicated or natural FET's? Consider switching to the other of what you have already had. I did a natural FET and felt great for it. This is not likely to have been the reason for my BFN.
The chances are - it will come right for you and I. We are very lucky in that we make good blastos and so many people struggle to get to that stage. But it is sooooooo bloody hard isn't it. I have been very down lately.
Good luck and stay in touch. x