Does a pe resolve on its own? my sudden chest pain with short breath since yesterday is getting better little by little with aspirin every 6 hours

No: Pulmonary Embolisms do not generally resolve on their own and in fact will become more extensive over time if the source of the clots, usually a DVT in the leg is not treated. Its possible to have a small PE that doesn't compromise your breathing enough to notice. if you really think you have a PE you need to go to the emergency room right now but i'm not sure why you think its a PE.