Lump didn’t show on ultrasound

Hi all, 

I was referred to the breast clinic after noticing a lump in my breast, my GP confirmed he could feel what I could and thought it was normal breast tissue but referred me anyway. The consultant again confirmed he felt the lump and said he was confident it was Fibroadenoma as I was young (25) I had the ultrasound and the radiographer again felt the lump and proceeded with the scan... she told me she couldn't see anything no cyst no or fibradenoma and she was confident I could just feel the edge of my breast tissue.

of course I was relieved, I'm assuming I will get some confirmation of the results at a later date. But Now I've had time to think I'm a little worried why nothing showed of we all could feel it? 

does lumpy breast tissue "look" like normal breast tissue on an ultrasound? Has anyone had this experience? 

I'm in no way doubting the radiographer I just wish I had asked there and then :)