I have a stabbing pain, on the left side of my bellybutton and is moving to my back, its not consistant what couild be doing this?

Many things. It can be different things- your kidneys, your GI tract, ovaries, ... Cqqheck with your pcp if it continues.
Many things. Consider muscle strain, kidney stone, kidney infection, GI problem, groin pain, bladder problem, and back problem. If no surgery or trauma, would think GI problem but monitor. If worsening pain or symptoms, seek doctor advise.