New here, suspicious fibroadenoma and waiting for biopsy results

Hi everyone. I'm 39 years old. No previous cancer history or family history except I was diagnosed with juvenile papillomatosis (including some atypical ductal hyperplasia) at the age of 23. That entire side of my breast tissue was removed and it did not recur.

Flash forward to today, except involving my other breast. I noticed a lump by accident when I bumped it last week, and given my history, called my clinic immediately for a review. My breast doctor felt it but was not concerned- despite that, she sent me on for a mammo and ultrasound. The mammo was inconclusive (my breast tissue is too dense) but the ultrasound showed a solid mass about 1.5 cm. It was actually the same spot as a fibroadenoma that I'd had biopsied 1.5 years ago (could tell by the coil they placed in it), which at the time appeared rounded and smooth, as fibroadenomas should. The lump was different though. For starters, it had grown .5 cm, and it no longer appeared as regularly oval in shape... borders seemed fuzzy.

The radiologist reviewing my films had about 2 years experience and told me "fibroadenomas don't grow" and indicated this was a very concerning finding. He biopsied it via a core needle procedure, but I won't have the results for 2-3 days.

Of course, I am freaking out. But two questions for this great community while I wait...

1. Is it true that fibroadenomas don't grow?

2. How common are irregular borders in a fibroadenoma? He indicated it was "mostly oval" but that wasn't helpful. I've requested a copy of the report and will post it when I get it-- but seeking a little clarity between then and now so I don't drive myself insane.

Thank you in advance!