It's so hard to play the "Wait and See" game. I've asked this question previously of someone else...did you have your x-ray and ultrasound done at an imaging center, and not at the Doctor's Office? If so, you will more than likely be able to pick up a copy of the radiologist report. When I've had scans done, the information is available the next day. I know that many doctors prefer to go over the results with your personally, but if they won't be available for an extended period of time and the wait is too much, it may be an option.
As for smoking, I was told that 15 years is pretty much an all clear. But, it also may depend on the length of time that a person smoked. If you smoked for a greater length of time than you haven't smoked, it may be different.
A spot can be many things, scarring, evidence of a collapsed area of lung tissue (atelectasis,) or even a shadow. If you don't have COPD and haven't smoked for a long period of time, the odds of the findings being minimal are better. Hoping for the best... always.