Is it normal for one butt cheek to be bigger than the other shortly after BBL?

I wouldn't say that is "normal" but it is not unheard of. Only your PS will know for sure why this is happening. There are a lot of options: 1) more fat was injected into that side  2) the fat was not injected uniformly or exactly the same as the other side  3) the buttocks were not completely identical to start with - there were asymmetrical 4) there could be more trauma on that side - a hematoma or just increased swelling due to more trauma.Give it some time to settle down - it can take 2-3 months for swelling to really calm down. You can then reassess with your PS and make a decision on possible revisions.

First, all patients are asymmetric before surgery.  The two buttocks may heal at differnt rates as well. Give it time to settle down.

What you describe is not normal but can happen.There are a variety of reasons patients may have early asymmetry after a BBL.This may or may not resolve with time but final results should not be judged before 3 to 6 months. Please follow up with your plastic surgeon who can help you address your concerns.Best,Mats Hagstrom M.D.