So in January I was diagnosed with PCOS and started on Metformin. Within two weeks I noticed my left nipple was sore. I chalked it up to hormones. After a few weeks and it was getting worse I felt a lump in my nipple. I went to the doctor who discovered an abscess. After sending me for a US and Mammogram which were both normal, they manually drained the abscess. It came back. It was a cycle, drain it, it came back etc etc. So 6 weeks ago I had surgery to remove it, I healed quickly with no complications. 2 weeks ago I was increased from 500mg to 1000mg of metformin and Im having the EXACT same nipple pain for a few days now. Not incredibly painful, mostly noticed if I brush against something or when I am exercising! I suppose I will call the breast specialist tomorrow, but I'm wondering if this sounds hormonal to you? Is it possible the abscess is coming back? Could it be scar tissue?!?!? I thought I was done with this!