What Causes A Painless Bump On The Stomach?

I have a mass to the right of my bellybutton, it is painless and my bellybutton has begun to "push" out.... before this a few years before when cleaning my bellybutton I had noticed a small knot but as it was painless did nothing about it. I wonder now if that small knot is now the mass that I feel when on lying on my side it cannot be felt otherwise... it seems to be quite large... is hard and unless direct pressure(washing dishes leaning into the sink) there is no pain. I had seen a doctor and he suggests a bellybutton hernia I am concerned about this because he said that nothing is done...but I have read otherwise... Am I wrong to worry?