Question about MRI results

I'm 41 and had a baby eight weeks ago. At about 32 weeks I started having some brownish discharge out of my left breast (not spontaneous), along with some on-and-off tingly pains. An ultrasound was clear and the discharge stopped. Then, after my daughter was born I experienced a huge imbalance in my milk supply, with that side being significantly lower. This is my third time breastfeeding and I've never had this issue and so was concerned. I went back to the breast surgeon and she ordered an MRI which was denied, since I hadn't had a mammogram first. When I went for the mammogram they switched me to another ultrasound since I was nursing (also clear). When she ordered an MRI again, they denied it again until she shared the extenuating circumstances with them.

So, after a six-week hassle with insurance, I finally got my recommended MRI on Wednesday. I called for my results today and my surgeon is out of the office until Tuesday. Because I requested them, the receptionist got the okay from the on-call doctor to give me my results. She told me that they wanted me to get an MRI-guided biopsy on the 23rd because something was lighting up. She stressed that there was no mass, but because they didn't know what was "lighting up" that they wanted to do the biopsy to be 100% sure. My surgeon is going to call me on Tuesday to discuss it with me further.

My best friend, who is a neurologist in the same medical system, looked up my results and it said that there was expected enhancements due to lactation, with more enhancements on an area on the left side. Her impression from the results is that the biopsy is more a result of the MRI and the discharge, rather than just the MRI findings alone and that if I hadn't had the discharge that they would have chalked it up to lactation.

Anyone have a similar situation? Should I be encouraged that there is no mass? This whole process has been so anxiety-ridden and has certainly stolen some of the joy of having a newborn. Thanks in advance for any insight you might have!!