I have fibrodenoma last 2 years. Now there is pinching pain sometimes. What does it means? Is it changing into breast cancer?

Not likely. If your doctor is absolutely sure that you have a fibroadenoma and nothing more. In general, breast cancer is uncommon at your age, fibroadenoma does not turn into cancer, and cancers are not painful. But these are general statements and exceptions occur frequently. Best to see your doctor for specific advice about your case.
Fibroradenoma. Fibroadenoma's are benign and rarely become malignant. Most malignancies of the breast present as a painless lump. Seems very unlikely.
Not likely. Breast fibroadenomas are a common benign nodule that does not become cancerous. Have you already had a biopsy to confirm it is benign? Pain is also rarely a sign of breast cancer ; breast pain is more commonly associated with fibrocystic breast discomfort around the menstrual cycle. See a doctor for an exam to be sure there are no concerns.