Welcome @melissamills73, It sounds like your pulmonologist is taking great next steps in ordering the PET and blood tests. Lung nodules can be caused by many things, and some people have them and don't even know it. But it's good to take this finding seriously and follow up. While waiting, I generally try to keep my life as routine as possible. And I try to remind myself that if there is something there that needs action it's best to know about it, and worrying won't change the outcome. Let us know how the PET scan goes. Have you ever had one before?
Here's a link so you know what to expect:
https://www.mayoclinic.org/tests-procedures/pet-scan/about/pac-20385078