So I've been taking BJJ and Muay Thai at a small school for about a month now. Last wednesday we were drilling sweeps. It went well at first, but right at the end of drilling I caught about 3 feet of air from a sweep and immediately felt something wrong in my upper right side of my back, just below my shoulder blade. My partner didn't do anything he wasn't supposed to, although I think him having atleast 50 lbs on me didn't help. I felt a sharp pain everytime I did something involving my lat area for the next 4-5 days. Its dull now but yesterday I started feeling like I was bruised on my ribs on the front of the same side. Any thoughts on what might have happened? what should I do? should I roll tonight? Thanks.