Second biopsy

I turned 50 in December and had my first mammogram early January.  I was called back to have an ultrasound and a biopsy (2 samples taken). They telephoned me last week (on the day I was due to go to the hospital to get my results) and said that the pathologist report said it was benign. However, they said I had to go in for a second biopsy via the mammogram machine and they took 7 samples. I asked why I have to have a second biopsy if the results have come back benign. The radiologist said that the pathologist report does not match the mammogram findings. I get my results on Thursday. To be honest, I'm not feeling too anxious and don't want to meet worry half way. I just wondered if anyone else on here has had a similar experience.