breast lump... fibroadenoma?

I'm new here. And I'm not familiar with breast ultrasounds or mammograms. I am 27 and just had a dr visit with my obgyn to go over my medication for my pcos. Aside from that, I found a small bump on my breast a few weeks before that appointment and and, since I had that appointment set up, I told her then. She said it could be a fibroadenoma but she couldn't know for sure. So she called down and I went right in for a ultrasound. I really didn't understand all I was seeing. Then the tech said the radiologist would come in to take a look and feel around. Which was fine with me. He had her put up color on the screen. Which I was then told is blood flow. I guess the blood flow right on my limp was pretty crazy. But I don't know if th bad or good. Is that normal? He then said to do a mammogram so I went and did that right away. Then after a bit he cqe.back and showed me the pictures from the mammogram. You could clearly see the lump. He was thinking it to be a fibroadenoma. But told me we should do a stereotactic biopsy. I said ok and made the appointment for the fallowing week. I went home to do some research because I have no clue about any of this stuff. I read something about blood flow over lumps being cancerous because cancer needs a strong blood flow. True or not, I don't know. I became concerned but everything I read soundest in my favour. I went in for my biopsy and it wasnt all that bad. Weird and uncomfortable but pretty much painless. I took a couple more images after (with the clip in place) and was then told that he would call me in 2-3 days with the results. Well today (3 days later) I recievws a call from a lady in radiology saying she needed to schedual a appointment for more imaging. So I go in tomorrow morning. I'm confused. Why do I need even more imaging? Why didn't I get my answer on the phone. Now I'm worried. But why would I have been told fibroadenoma if they don't think thats what it is? They would have told me if not. I think? Has this happened to anyone else?
*forgive me if my spelling is bad, I'm typing on my cell and it has a mind of its own most times :) Thanks!