When ever my left breast get touch it starts hurting, I went to the dr. they said everything was fine.. I don't know what's wrong?

You may just be sore. It could be pms, it could just simply be growing. Get a second opinion if pain doesn't subside.

Then don't touch it.. Just kidding.

How old are you? Any medications? The doctor that said nothing was wrong... what kind of doctor was he? Could you be pregnant? Do you have a family history of breast cancer?

You see, there are many variables you left out in your original question. From what you have posted it is IMPOSSIBLE to even venture a guess as to what the problem could be.