Sore Leg After Being Hit. Why Is The Chest Muscle Paining? Related?

Two weeks ago yesterday, i was jumping a horse and we both hit the dirt going over a fence (he forgot a leg and got caught up in the fence) and i was sore the next day but after a few days, i was fine. A week after the fall, I woke up with sevre pain in a muscle on the right side of my chest running under my breast ( I landed on my right side from the fall) and a week later, the muscle is still sore. Sometimes it is enough to take my breath away depending on how I move or stretch . The ribs themselves feel fine, I can take deep breaths and when I push on the area, the ribs don t hurt, just the muscle. I have had a broken rib before and this pain is nothing like that. I m just wondering if this is a bruised/strained muscle or something else. Thanks