Breast Cyst. And what should i do?

I had a hard painless lump in my left breast , a smaller one, whenever i touch, it seems something hard muscle kind and it moves. I consulted doctor, she told its fibroadenoma. Its not harmful and natural with many females, its just stays and nothing happens,". Nothing to worry about it. But sometimes now a days, after couple of months, it pains sometimes not exactly the cyst areas, but all around it. Sometimes only. Also i feel sometimes its bigger than before. So sometimes on pressing it pains little. So what exactly it is? We need to be worried? Should I consult doctor again?? No other symptoms are there. But will this effect me anytime in future!? What exactly it is happening and what should I do?