How To Treat Sharp Pain Between Shoulder Blades And Chest?

I am having pain between my shoulder blades. It is a sharp pain that comes and goes every every few minutes to every hour. If feels like it goes across my shoulder blades and into my chest. It has woken me up the last two nights and I have taken tums assuming it s heart burn even though I haven t had heart burn since I was pregnant and it felt different. Could it still be heartburn?