Pain after training

I’m not sure if this is the right place to post this so if not I apologize in advance. I have been training and following sslp for a while now. I’ve been using a belt and working hard on bracing. I’ve noticed after training I have a few concerns with the stomach area. I thought maybe I was bracing incorrectly but I don’t think that’s it. I notice that after training my stomach and sides hurt. I’m thinking this is caused by my belt. I bruise easy but I don’t know if it’s normal to have these types of aches and pains? Ive never trained with a belt till I started sslp so the belt is fairly new and I tried to break it in but it could need some more time and this could be the issue? It’s a 3” 10mm single prong belt.