Pain easing is a good sign, but pus with a trace of blood still coming from the nipple means the infection hasn't fully settled yet. This can happen with an infected duct or a small abscess under the nipple that needs to finish draining and heal completely, even after the antibiotics have worked on the pain and swelling around it.
Next Steps
Finish the full course your gynaecologist gave you, and please see your gynaecologist again this week for a recheck, since ongoing discharge usually needs an ultrasound to see if any pocket of infection remains. Keep the area clean and dry in between.
Health Tips
See her sooner if the lump grows back, the area turns red or warm, you get fever, or the discharge increases.