I see, Ash. Over here, if you choose to go down the route of adoption, you are not allowed to in parallel still be going through any fertility treatments. Plus (did think of it) - I am too old to be able to adopt a baby... You are still young, so I suppose that doesn't really factor in yet
At the end of the day, I suppose it is wanting to be a parent - and you can be a parent and give a child a good, loving home, without the child being your biological offspring
As you know, we went through many many cycles before we got our BFP - and it was basically explained that even if an embryo looks good on the outside, on the inside it may not be healthy - and if all other parameters (hormones, lining etc.) are good - then it is just likely that the embryo couldn't survive : i.e. nature "interferes with science". Our doctor had said to us, that he did believe we would get pregnant, he just couldn't tell us how many tries it would take. ... and he was right!
The only way to really know whether or not the embryo is good, is to have PID done (which we didn't have done, because we never had that many blastocysts develop per cycle) - and otherwise, just keep fingers crossed that the blast transferred is healthy and can continue developing.
As much as science can do and as far as we have come with it (so many of us would not be able to become parents without the miracle of fertility science) - at the end of the day, it is still Mother Nature that holds the key and the outcome in her hands