I Recently Had A Puncture Wound From Falling On A

I recently had a puncture wound from falling on a metal pipe on my left side about 5" below my arm out. In the emergency room they cleaned the wound and closed it with 12 stitches. Now 3 days later a large lump has formed about 2" below the wound. About 4" long and about 2"tall. It is hard to the touch. No pain when touched. I have tried applying both heat and ice packs but no changes to it. There is no redness or warm feeling come in from it. It feel solid and hard. What could it be?