Two days ago, the middle part of the left side of my back started twitching. I have no pain, but its annoying. Almost as if someone keeps poking me.?

Fasiculation? Fasiculations are involuntary contractions of a muscle. If there are no other neurologic problems (such as weakness or sensory loss), they are typically "normal." people just get these off and on. However, if they persist, it is good idea to be seen by your doctor so your electrolytes can be checked.