Chest pain does not always indicate a heart attack (MI, heart cell necrosis), but it could indicate angina (chest pain, etc.) due to the heart not receiving an adequate supply of blood...usually happens when there is exertion and goes away immediately with rest (but not always, usually).
A nitrate medication can relieve angina by dilating the coronary arteries (usually). Yes, there is evidence that women experience different pain due to angina and a heart attack and the pain can rediate into the back area as well.
If you are having a heart attack...can't be ruled out...a blood test will have markers in the blood supply for a short period of time (72 hours) indicating dead heart cells from a heart attack. Requires going to emergency as soon as possible, and if it is a heart attack a quick response will help save heart muscle.
And sometimes one can have a "silent" heart attack and no immedicate symptoms until heart failure symptoms.