Large yolk sac and success stories

Hey all, I've been in this in between state of pregnant and most likely not pregnant for almost a month now. Today I finally got a heartbeat. I'm somewhere 6 weeks and 2 days and 7 weeks and 5 days so there's a large indeterminate gap from FET day, unknown implantation, and gestational date. Today showed a 5.9mm yolk sac so drs are still in the most likely going to miscarry mindset. Anyone have experience with large yolk sac?