Why Don't I Feel Better?

We weren't home when the pediatrician called with the ultrasound test results. In a quiet message on our answering machine she said some thing I didn't understand, plus the words "the radiologist said everything appears normal." We listened to it multiple times to make sure we heard it correctly.
These were the words we wanted to hear, but they didn't make me feel better. Maybe it was the drama from the ultrasound techs trying to figure out if the bump was a lump or a palpable mass. Maybe it was the doubts that conversation put in my head. I don't know, but I still don't feel settled about the whole issue.
I realize the radiologist's diagnosis is the final word as far as the pediatrician is concerned, but the brunette twin still has a 1.5x1.5 inch bump on the back of her neck. The pediatrician thought we should just watch it. I don't know how I feel about it. The brunette twin is self conscious about it now. She asks if you can see it whenever she puts her hair in pony tail. She feels it every morning to see if it's still there.
When the office calls about her blood test results I think we need to ask some questions. I don't know if those answers will make us feel more comfortable, but it might be a good start.