Your description sounds like common post operative changes. Swelling and bruising can track back towards your hips and buttocks as you lay on your back and the fluid naturally settles in those areas. Additionally, if any liposuction was performed significant bruising is to be expected. Do not hesitate to contact your doctor's office if you feel anything is abnormal as most surgeons are happy to have a quick visit to relieve anxiety if there's nothing wrong and would rather see you sooner rather than later if there are more serious concerns.
Its not uncommon to experience swelling and bruising in the hips and buttocks after tummy tuck surgery particularly if your procedure was combined with liposuction to help achieve improved asymmetry. Keep a close eye on your progress and advise you surgeon if you are concerned.
It's not unusual to have significant swelling in the hip and upper buttock are following an abdominoplasty surgery, especially if some liposuction was performed over the areas. However, let your surgeon know about this situation. They may want to see you back in their office sooner that previously planned. Best wishes, Dr. Lepore.
Being one week out there is expected swelling as you know. It is not all that common to be swollen in the buttocks and hips if you did not get liposuction in that area during your tummy tuck. However, if you were my client I wouldn't be too worried about it assuming you've had post operative visits since surgery already. If you have anything that seems out of the normal postoperative course I would call your surgeon's office and ask to be seen.