Will keep good thoughts. Usually blood work takes 24 hrs. Hopefully they will rush the results for you. I'm thinking they wont get the blood to the lab until Saturday with the weekend you are looking at results on Monday.
Most labs dont work on Sundays. We had blood work done for RB Butterscotch on Saturday a.m. and got results Monday a.m.
I would not expect results much before Monday.

With his symptoms etc, I would have him retested tonight for feline leukemia etc (you will get results in 10-15 mins) before they go doing a full CBC (complete blood count) on him. You'll save him the experience of blood draw and you the cost of CBC. Thats my advise.