There's no way for them to say definitively that is the cause. But you didn't give much information here on the quality or timing of pain. Is it inside your chest, or on the outside? Is it near your breasts, or elsewhere? Does it happen only when you are feeding, before or after feeds, or randomly? Do you experience any related symptoms like shortness of breath, or cold clammy skin?
All these questions are relevant to the assessment (don't know if you considered these at the doctor or not). But if you feel that the pains are not associated with feeding, I'd keep consulting your doc, even if it's just a phone call.
General chatter while we wait (and commentary on the "pull out method") (4 Viewers)