Not sick but coughed really hard and now my sides hurt>?

I was inbetween sets during my workout, and i got that kind of feeling when it feels like saliva went down your windpipe. So i started coughing via my gag reflex, and so my last cough was really big, and immediatly after both my sides really started to hurt. I decided to skip the rest of my routine because it still kind of hurts and i dont want to risk any injury. I am not sick or anything. Any idea as to what this might be?