Yep, I'm a fainter as well. Not always, and no idea why. Had a batch of tests recently, 3 out of 4 I was 100%..... Like most people I suppose, I've seen plenty of my own blood over the years, as well as bits that shouldn't see the light of day under normal circumstances, accidentally inserted all manner of things that shouldn't be inserted into people (no, not like that!! I mean sharp objects, bits of glass, nails, screws, assorted tools puncturing assorted bits of my skin), stabbed myself, sliced myself, burnt myself, bounced myself of solid objects at bubious speeds etc etc. Used to do martial arts and would often cover about 90% of my body in large and deep bruises, never bothered me at all.
The thought of the test doesn't bother me whatsoever. The thought I might faint like a huge great ******* whuss, now that's starting to wind me up. Last time I offered to do bookings for when they have a trainee in.
I have a mate who is so terrified of the idea he can't bear to do it - runs away, litterally. Posed a propblem when he got infected with TB recently.
My missus passed out at home when we were about to do a DIY cholesterol test....but she's fine with jabs etc.
I think it's just plain weird and totally beyond your control. Had a trip to A&E a wee while back and had some bloods taken. Doctor had to use my wrist as both elbows previously used that day and she warned me it would be unlpeasant - no idea why, it was fine, as was I on that occasion. She said I must be over it if I could take that one OK. She was wrong, sadly. Seems that if you are prone to Vasovagal Snycope, you are stuck with it - it's just the way you are wired up.