Pus and blood coming from left nipple when squeezed
About 5 days ago I noticed that my left nipple was sore. Three days ago I noticed it felt hard and swollen on the inside, sort of like behind the nipple. So I looked at it under a bright light and squeezed it a bit, and it popped like a big pimple. A big drop of yellow/green/white liquid came out. It had a little tiny bit of a blood colour to it aswell.
I went to the doctor yesterday and she thought it was an infection. I was prescribed antibiotics and have taken two so far. I squeezed it again tonight (24 hours after the doctor's visit) and some more yellow/green stuff came out, but then it was followed by blood. Not very mich blood, but blood nonetheless. It feels like there is a long tube going from behind my nipple deeper into my breast. It's hard to describe but it feels very different from my right nipple, which is completely fine.
I have never experienced anything like this before! I will be going back to the doctor on Friday for a checkup but I was wondering if I should go back before because of the blood that came out and she said to come in if anything changed? What could I possibly have?
Thanks for your help.