Advice Needed Regarding BBL - Brazil

I just had my BBL yesterday i spent the night at the clinic,a few hours after the surgery I went to the toilet to pee,I looked in the mirror to have a look at my butt! I saw no difference to before although my doctor said he placed about 500 cc to each cheek! I asked him about that and he said don't worry the fat will drop down with time ..
I really don't know what to do know
And he said I can sleep and sit just normally on my buttocks but I read that 90% of the surgeons recommend to avoid sitting on them
Really confused,please help!!!