Zaphod 3000. I doubt your pulse was really 42 even if you are training for the olympics so I suspect ALL the readings were inaccurate. The diastolic is the one that doctors worry about (ok chaps lets not restart that thread) and yours is fine. Dont forget your blood pressure was checked for your class 2 and must have been OK!!!
Even though feeling well and exercising does not guarantee normal blood pressure, I very much doubt yours will be raised at your age. If it is you would have some serious medical issues and it seems you dont.
So I would forget the experience and go do your medical!
For anyone else wanting to self worry, so called cheap machines are fine but they need to be made by a reputable company. Omron is my recommendation - I have no interest in the company, but have bought them for under $50 and they are reliable and last for years