5 weeks post op, I have a small pouch under chin after lower face lift and neck lift. Is this normal? (photos)

At only 5 weeks out there is some residual swelling. If this is the case then it will continue to fade away. Also since you state you had a neck lift, just from the liposuction part itself you should have some skin contraction which will improve this area too. Skin contraction will start at about three weeks post op and continue for months. Be patient and you should see this area improving over the next 6 months. Please follow up with your surgeon. 

It is very common to have a little residual skin abnormality after surgery. Sometimes swelling, fluid collection or skin texture can contribute to this. Continue to wear your neck brace, consider using Nectifirm twice a day and see your plastic surgeon for his assessment. Good luck and thank you for your question.

Since you are only 5 weeks post op, it sounds like you have some swelling in the area.  Follow up with your surgeon, and inquire it you should continue wearing the neck garment for another week, maybe at night.  Best wishes!