Had chest pains when to urgent care they said gerd. ran a chest ct found tiny clot in the bottom of lung. i am low risk no family history or bc pills. how could something like this show up? he said it would dissolve on its own can that happen?

The information provided is insufficient to be able to comment specifically on what you have, but obviously it is not something your doctor believes will get worse or requires further treatment. It is not even clear that it is something that is associated with family history or use of birth control pills, but we often cannot find an obvious cause for things, even when you are "low risk."