I'm not sure if my rib is cracked?

I was fighting with my friend for fun, and i didnt feel any pain at the time, we were drinking but i wasn't really drunk. The next evening i felt pain under my left pec. Now two days later it still hurts, it doesnt hurt to breath but if i laugh or cough hard it hurts slightly. It also hurts when i stretch my arm back, but not really if i lean it forward. It doesnt look swollen and there is only a small bruise.