Hi 2 dogs:) Welcome to OCF. The support you will find here will be wonderful, I promise!!
My experience with the PET was there are a lot of false positives. My first doc wanted PET's every 3 months. Then I switched doctors and she doesn't do them at all, doesn't believe in them. So, try not to worry about the "light up"
I didn't have chemo or radiation but I have learned a lot from the people here and I'm sure more will chime in. I know it can be a long process for some. So, take your time, enjoy your small victories and you will be just fine.