How to know if I have shin splits?

I’ve been increasing my miles getting ready for a marathon. Ran 15 miles Saturday at a very slow pace and noticed my shoes had lost their pop. Got new shoes and have ran 3 5ks since then. I don’t experience pain while running. But mainly once I get home and actually relax on the couch is when I notice shin pain. Nothing crazy. Just a dull pain that comes and goes. It makes me nervous because taking a break from running would ruin my training schedule. Everything I google points to shin splits but the fact that it doesn’t hurt while running makes me wonder if it’s not just some soreness.