This Forum, deals only with breast cancer issues and I am really sorry if I cannot be of any help regarding your CT scan results.
You should discuss all of this with a lung Specialist and/or your primary care doctor and ask them the same questions you have asked here.
Wishing you all the best...
My worry is that it is breast cancer mets to my lungs. I was diagnosed with triple negative breast cancer 3 years ago and now worried about recurrence.
I can certainly understand you worrying about recurrence...but for now, I don't think that you should be overly concerned,since the Doctor recommended a 3 months follow-up to check if there are any changes.
Hoping you won't have to worry about anything also on your next CT scan.
Sending prayers and good wishes your way...