I think CD9 will be too late, I am sure it has to be done between 2-5. Is there a local hospital that has a walk-in blood service, with mine I can go any day (apart from weekends) you just take a ticket and wait. If not, ask to speak to your GP and see if they can fit you in, sometimes the receptionists don't understand the importance of these things needing to be done on certain days x