Will the fat from the top of my BBL drop to the bottom? It looks nice & round at the top & super flat at the bottom

The buttock tends to drop and round out a bit with time as swelling and hardness decrease.  Early in recovery, the swelling can really distort how you are going to look.
Kenneth Hughes, MD, Board Certified Plastic Surgeon
Los Angeles, CA

Thank you very much for sharing your concerns with us. Eight days after BBL it's not enough to express a valid opinion of results. I recommend daily lymphatic drainage massage therapy 5 times at week for the next two months, and wear a postoperative girdle for two months at least.Kind regards,Dr. Emmanuel Mallol Cotes.-

Hello dear!!
Thanks for the question and provided information as well. 
You are still early on the healing process, it can take up to six months to see your final results, so please be patient. 
If you have any concerns, please follow up close with your plastic surgeon.
Good luck :)

8 days is very early in your healing process. The final result will be different than what you see now as 30-50% of the fat volume injected is lost over 3-6 months. Give everything time to settle in.