I am A Pos. Know this from when I was a blood doner.
However, some forty years ago, I had a very bad fall, which resulted in a lot of internal bleeding and twice the hospital tried to give me blood, and both times I went into 'rigour'. I hace no idea why and what they were doing wrong. This was not immediately after I went into hospital, but the first attempt was when I had been there a week, and th e second one two weeks later. Theygave up at that point.
I was very worried when ten yers later I needed a major operation - but that time, they got it right, and had no problem with the blood infusion.
My Covid Vaccination card, is carried with me at all times, I am worried that I could lose it, so have photographed it, and keep a copy both on my phone and on my laptop. Both jabs show date, batch nos. and type.