At What Point To Should Someone Seek A Second Opinion.

At what point to should someone seek a second opinion. In the ER they took a CT scan of my ab and pelvic area. And there were enlarged lymph nodes, chains. Which they said could be secondary to metstatic disease. I have had a colonoscopy and a mammogram everything was ok. The surgeon that I should have a CT of the chest and neck, but wanted to talk with the regular X-ray MD when he got Bach from vacation. Yesterday I received a call from the doctor's nurse stating that they want me to monitor my weight for the next three months and if I lose more weight call them back. Family and friends are telling not to wait....am I wrong to wait?