Mammo in 2006 said probably fibroadenoma, sono in 2006 inconclusive. 2009 sono birads 2. no followup after that. no chance in size. should be worried?

You need follow up: If you are 33 now , breast lump was diagnosed at about 20 yr age , fibroadenoma (s) common at that age, and no follow up for 5 yrs , you need to see a breast surgeon , for evaluation , possible image guided core needle biopsy . If diagnosis is fibroadenoma a benign lesion removal is best option or it can be observed will not disappear , now it is up to you .

Probably not: as from what you are describing the "fibroadenoma" hasn't changed in say 3 years. Nonetheless it doesn't mean ignore it. If you haven't had it checked since 2009, it would put your mind at ease to check it now.