Yeah, i am pretty sure that i was the first person to bleed in my mountain biking class:  today was our first time on the trail.  My best guess is that when my bike started falling over (and i planted my foot) is that the pedal connected with my calf.  The stinging pain lasted for an hour, the adrenaline for about forty-five minutes, and last i checked the wound is still oozing slightly.  It gushed pretty good when i tried to wipe it off, which wasn't the most sanitary thing to do because i had gotten gas right before class, put some oil in the engine, waited five minutes for the bathroom to be vacated so i could wash my hands and empty my bladder, and ended up leaving so i wouldn't be late for class (i was still a bit late, but not the last to arrive).  The class didn't go well, it was hot (mid-90's), the adrenaline made me nervous, and i'm behind on the learning curve, unfortunately.  On a completely different note, why do my legs look so trim in real life, but not on film/flash card?  Beware!  It's a little gory:
ETA:  The manager at the Bike Shop said that it looked like my leg connected with the chain ring, which is actually what i thought had happened, while my teacher had said that it looked like the pedal.  I especially liked the spirals, but they faded after one day.