Period and Nursing

Anyone else still get a period while nursing? I went in for my post at five weeks, and now I’ve bled for a 8 days. What was just bleeding from the IUD implant has definitely turned into a period. My third baby is the best of my three nursing, and I have more milk coming in based on his overall weight gain. Will having a period lead to less milk supply? The floor of my vagina has a searing pain at times, otherwise no cramping at all has started.