what is Fibroadenoma

I noticed a while back that I have a little lump in my right breast and left breast both in the same place.
I can only feel them if I dig my fingers deep into my breast.. it's on the side.
Which I told my friend about as I was worried and her mother (nurse) said that it's more than likely Fibroadenoma 
I'm 20.
I noticed them last year when I started doing breast exams.
I'm currently 12dpo and my breast are super super sore, itchy, I have sore nipples and shooting pains in the right one but that has now gone.