No medical staff should try to diagnose someone with or without an aortic aneurysm with only plain X-rays!!! Usually, they don't even appear on it. An echo has to be done or a better option would be an MRI! It may not be rare to have an aortic aneurysm at your age if someone has some conditions that increase their risk like, marfans syndrome, EDS vascular type and very weak blood vessels that leads to dilating of blood vessels. If aortic aneurysm is your problem, immediate treatment(beta blockers or surgery) must take place to prevent a dissection or worse, a rupture. Hope you find out your problem soon! Good luck!