Boobs sore after stopping combo pill

mw0904 • 1 🌈, 2 👶 💙 💙

Hi! I am 6 months pp and took the combo pill for one month. I had some terrible side effects so only took one pack and now I’ve stopped. My boobs are so sore since I stopped. Took a pregnancy test yesterday just to be sure and it was negative (had my withdrawl bleed last week) so I don’t think I’m pregnant. Any ideas?