Intermittent pain under shoulder blade for 3 days. female 70 years of age?

Hard to say: More details please! How long does the pain last? Is is sharp or dull? Does it happen with movement or at rest? Any other symptoms? Atypical chest pain can be serious or minor depending on all these things, plus your medical history. If the pain is only with movement, it is likely due to a problem with your muscles. If not, lots of causes. See a doc. If shortness of breath, nausea, pain to ER.