A few days at least, I think. I had 6 x core punch biopsy on Tuesday and my breast is very bruised, still a bit swollen and sore etc. It is improving though. If you're getting worse or seeing any signs of infection, do see your doctor. 

Hello and thanks for posting,

After a breast biopsy, the breast can feel bruised and swollen for up to several weeks. Wearing a supportive bra such as a sports bra can help.

If the area becomes red or sore, then do seek medical advice.

I hope this helps,

Best wishes,

Vanda