Umm, I'm bleeding?

Since last December, I've donated blood every time the drive people come to the lab. Today was my third time. I usually get a little woozy when they pull out the needle, but today was bad. Like spots-over-the-eyes-and-the-room-is-humming bad. My nurse quickly noticed, and in one swift movement, he reclined my chair, elevated my feet and called for a cold compress. The one thing he forgot: the hole in my arm, where blood began to seep from in big drops. Is it actually considered "bleeding" if you're already giving blood? I'm not sure, but it freaked me out, and after staring at the growing drops for a couple seconds, I managed to say "Ummm, I'm bleeding?" Yes, like a question. Not sure why, that's just the way it came out in my hazy state. The nurse got the point, though. He bandaged me up, although left some of the dried blood in the crook of my arm, which I quickly cleaned up after a full recovery thanks to mini doughnuts and apple juice. Yuck. How does this bug me when I can stare at the blood-filled tubes or donation bag without any sort of reaction?