New lump scared questions?

[Alice]

Hi ladies,
I don't want to be paranoid but sometimes it is hard not to be.
I finished chemo in september and had surgery oct 7. Now waiting to hear if I'll be doing radiation.Soon to start herceptin for the ballance of the year.
I had a pet/ct done in march all was clear at that time.
Now I requested a ct of the head due to ongoing headaches all thru chemo and they haven't gone away since chemo stopped.Now I have found a lump in my neck. It isn't verry big and is located below my chin on the same side as mastectomy.
Does anyone know if the ct of the head will include the neck and if so does it show if there is a malignancy in soft tissue?
My original diagnosis was IDC stage 2 grade 3 er/pr- her2+++
any info you can give will help ease my mind. My ct is on 11/22 so I will appreciate any advice you have so I can ask the right questions.
Thank you all for all you do for me
Alice