When can I sit for about 3 to 4 hours with no pillow after bbl surgery?

I'm 19 days post op as of today and have not sat down at all not even with a pillow. I'm loving my results as all my swelling is going down. My question is it safe for me to sit with no pillow around day 27 for 3-4 hrs? I know it's a random day but I had an dinner I wanted to attend and was wondering if I would be in the clear to not harm any fat cells. Also I'm very numb still in certain areas of my flanks does this mean I can expect to see more dramatic results in these liposuctioned areas?!