Sisters, just to share abt blasto, as I was initially supposed to do that but last min due to my lining which sort of showed some O signs, dr said better dun wait for 5 days. But before this, dr shared w me that for blasto, he needs to use 6-8 embies to culture and there is a chance none will make it to blasto stage. (ie. Cycle aborted). But usually, if by D3-4, if progress of embies seem slow, clinic will call u down to do ET alrdy as it's better than aborting cycle. But the prob with this is, u will be trsfg embies that are slow in growth, so chances that they will implant is also much less. Dr said as much as their culture mimics the uterus, there is no way for it to be as good environment as our uterus itself. So put it in another way, the embies that didn't survive blast could have survived better in the uterus if put in earlier. But of course, if the embies survive 5day to blastocyst stage, the chance for preg is also much higher. So gotta weigh the pros n cons lor. For me, as this is my 1st FET, I was most afraid of having no embies/weak embies to trsf if they didn't grow well to blasto stage.