electronic interference generated by blood?
Well, since no one else has responded...

Your circuit is just a Darlington triplet (well, I kind of made that name up since it's a Darlington pair with one extra level.  A Darlington pair can often have enough gain to act as a touch switch just from the tiny current that can be conducted across your finger, so a triplet could have an obscene amount of gain (theoretically over one million for the 2N2222), possibly even enough that it picks up current induced in your antenna by your body's electrical pulses.  I think that your elbow has a large nerve bundle running through it near the surface (your funny bone is a nerve, right?), so maybe that's what's its reading...

Edit: Also, I'm totally not saying not to keep experimenting with it; just what my expectation of what is probably happening ( and I'm kind of dumb anyway :P )