34 weeks pregnant and having sharp vaginal pains? Is this normal?

[nellina2009]

I can't describe, it's unlike a feeling I've had before, it really startled me at first, when I bent over to pick something up all of a sudden a sharp pain prevented me from bending all the way over and I shot back up suddenly because it hurt so much. When I stretch out and lay down it doesn't "hurt" I still feel the pressure, but the shooting pains aren't there. But any time I sit forward or bend over it shoots that pain in my pelvic area again...!
I haven't felt this yet, is this a contraction or what?
This is my first baby so I'm not sure what I'm supposed to be feeling???