Bike problem

Hey folks, I've been watching this site for about half a year now. The thing that made me come put of the shadows was this little problem with my bike that just started happening a few days ago. Whenever I first get on the bike, everything seems fine but once I start pedalling I can feel and hear a cracking noise coming from the left side of the crank. The cracking noise happens in midpedal when i put weight on the left pedal. It only happens once when I get on the bike but then if I do so little as to bike off of a curb its cracks again. Is the screw connecting the crankshaft to the frame simply loose or is it much more?
Any help would be greatly appreciated.
Thanks-
BTW here is my bike
(specialized hardrock sport disc)

The first pic is of the bike stock new and the 2nd is of where the prob is

bottom bracket is either loose or worn. Other possibility is the bearing in the pedal have gotten worn. Bring it in to your shop.

V is right,

try a differnt set of pedals, and then its the BB / Frame or the cranks to the BB?

beer and a bike shop are your new best friends

Also might be a frame crack, but I think option pedals, crank or BB is the cause

Alright thanks guys, I'll see what I can do about the pedals since I have another pair!
Then on monday its back to the shop.

There could also be grime/dirt stuck in the bottom bracket which a quick cleaning could fix.

if none of those suggestions turn out an answer
check torque on your chainring bolts
most likely not it though since it doesnt make the noise on your driveside stroke

ok, hey I was just wonderin if it's ok to still ride it today for a little before bringing it into the shop?

should be fine to ride still

ok
thanks