Lump in clavicle

Hello everyone.

I can feel a lump in my clavicle it's in quite treacky location a bit under a collarbone, not always easy to feel. I would tell it's about 2 cm, l can feel it with two fingers. I had a neck US and asked to look in my clavicle too. Radiographer wasn't happy but he looked at it briefly and said it's all look good and put on report that it's just 3mm.

Than l had a CT scan of neck and chest.

My question is if it is an enlarged lymph node  and was missed by Ultrasound, there no way it can be missed from CT scan too? Does anyone know if CT scan will definitely show all abnormal lymph nodes?

Thank you