I Smacked My Arm Pretty Badly Today At Work Off

I smacked my arm pretty badly today at work off of a metal pan on a table. It was stopped from moving off the table by the bread machine so it took it full force above my wrist on my arm. I held it very tightly for the longest time as it really, really hurt. My hand turned a grayish tone afterwards. My arm is bumpy now where the deep bruise is and it actually hurts to touch it there. So much so that turning socks inside out(I was doing laundry) actually hurts it(the fabric touching it). Should I be concerned? This happened around 12:30 or so this afternoon.