Swollen hard lump under right rib cage

Hi I'm worried about a swollen hard lump under my right rib cage I only noticed it on the off chance as there is no pain ect 

 

I've been to see my gp who is sending me for a ultrasound but its 3 weeks away  

 

Is it possible to be something harmless as I've done the usual and Googled it and everything is leading to liver cancer im 35 years old

 

It feels like its right on the last rib on the bottom and goes around slightly to the side 

 

I did ask my gp if he had any ideas he seemed to think it could be cartridge 

 

Anymore information needed just ask

Thanks