Strained chest muscle

Hello all!

I'm wondering if any of you have dealt with pulled or strained chest muscles. I believe that's what I'm dealing with - a constant dull ache in my upper body, in my chest only. I've already decided to stop lifting dumbbells for awhile to let the muscles rest. I think I have to stop any workouts involving planks, too. But I'd still like to do cardio if I can. Could that strain my chest muscles further?! The only exercise I can think of that wouldn't potentially cause any further strain in my chest is walking. But if I have to take a break from HIIT, or even low-impact cardio, I think I'd go crazy right now! Exercise is keeping me sane at the moment.

Has anyone else dealt with this? Do you have recommendations on workouts I shouldn't do, and what workouts I can do that won't cause further strain? I'll be discussing this with my doctor, of course.