Why is the crease at the bottom of my butt not round after BBL?

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. At the stage you are in, inflammation and irregularities are normal.
If you have any concerns, please follow up close with your plastic surgeon.
Good luck :)

Three weeks is too early in the healing process to determine the final results. Be patient and wait for full healing before deciding how you like the results. 

3 weeks is too early to evaluate your result.  At the end of the day, no matter how the great the surgeon some patients will never be happy.  The dynamics and technical aspects of trying to create something that is much larger with perfect shape when the starting point is markedly different can never be fully elucidated or explained adequately in a forum like this.   Although 30% of my practice involves revisions, I only revise about 0.6% of my own BBLs.  I can tell you that from doing the procedure thousands of times, healing is never perfect nor predictable despite perfect execution on the table.Kenneth Hughes, MD  Los Angeles, CA