Can someone please help me figure out what this is why I have it? No of my doctors know. All they do is lance it and give me antibiotics. Then it appears again 1 month later.

I’ve had it since the 3rd day I gave birth. It hurts and is filled with pus and blood. I’m currently breastfeeding and have been for the past 7 months. But like I said, all the dr does is lance it and gives me antibiotics. Then it appears again 1 month later. I’ve had it every month. They did a screening to be sure it wasn’t an abscess and it isn’t.