My Blood group tests have come back with different results…

[Jettyellow]

I took a finger prick test last year (where you dab the blood droplets on 4 areas of a paper pad and look for ‘clotting’ to determine the result). This came up as B+

I had a blood test from my arm recently as part of an appointment and this has come back as having O- blood.

How is that possible? Should I speak with them and explain, or is the finger prick test unreliable or could the lab have interpreted it wrong?

Was the first test with some private company you bought a kit from? likely to be inaccurate.