Recovery Time for a Puppy Being Treated for Parvo?

Anybody have experience with their puppy having Parvo and surviving? Our puppy, Oliver, has been in the hospital for 6 days (with true clinical symptoms for the past 4 days, we just caught it really early). There have been a lot of ups and downs the past few days, today was one of the lowest. He's just today had his first bloody diarrhea (only a few times before that with a few spots of blood).

I had a talk with one of the rotating doctors tonight (one that has not seen him before and she said she only quickly read his chart) and she made it clear she thought he should be feeling better at this point.

He's been on all the standard care since he got there, antibiotics, IV fluids, anti-nausea, etc., and had a plasma transfusion on the second day of severe symptoms (2 days ago).

I've read everything about parvo that I can get my hands on, and it all seems to lean towards at least a week, sometimes more, before seeing an improvement. I know I want to give him more time to fight it, but was told in so many words I should consider euthanasia.

Has anyone else experienced a puppy surviving this long, seemingly in the middle of fighting this absolutely shi**y virus, and the puppy dying? Am I clinging onto false hope? I've been scouring the internet, and it led me here. I am hoping for some recent stories of other people who have experienced this.