In the early stages when i was losing the twin between 7-8 weeks I had a 50:50 chance of carrying a successful pregnancy.

Then after 9 weeks Inanna didn't give me a sepcific figure but she posted this "After a heartbeat is seen on u/s the best indicator of wellbeing is the sight of a consistent and adequate heart beat & of course growth. You have this so that is an incredibly positive sign.", and you have had both of these, the HB has strengthened greatly which is a fabulous sign for a strong little bubba. Will be thinking of you when you have your scan, I understand your fears
Take care and sending you strength to get through the next couple of days xxoo