To be honest, unless you’re going for a transfusion in about 3 days, knowing your blood group now is a bit pointless.
I could have “DrP pro racer, blood group F-” stickers all over my bike/helmet/ass, but if I ended up in ED needing blood, they’d simply recheck my blood type there and then…
Same for work..there’s no situation where you’d need an emergency transfusion without someone (ideally medical) checking your type first, regardless of what you think it is.
Of course, my brain is small and it’s early, so you may need to know for another reason, but I can’t for one think of clear reasons why just now..
DrP