Chest pain across breasts and shortness of breath. I've had a norm stress test, echo and EKG two months ago. Serious heart issues ruled out?

Mostly. To answer your question, with a normal stress test, echo and ekg, most of the serious heart issues can be ruled out. However, given your symptoms, other differential diagnosis includes pulmonary embolism, underlying asthma, gerd, fungal pneumonia etc. Would need more history before we can narrow the diagnosis.
Non cardiac pain. It is important to see if pain is reproducible by pressing where it hurts. If it is reproducible it is usually chest wall pain, inflammation under skin. In females fibrocystic change is common which is a flare of cysts that are under the skin and are benign. Try an ultrasound of the breast to confirm. Ibuprofen will improve pain and avoid coffee, cokes, chocolate etc.
Yes. Your chest pain had a complete, negative (normal) work up. This is quite reassuring. Sometimes it is more important to know that chest pain is not the heart than to know exactly where is it coming from as there are literally hundreds of reason for chest pain and you may not be able to work up all of them.