Why Am I Not Looking Flatter After Tummy Tuck 13 Weeks Later? (photo)

It is definitely too soon to tell. You still could have swelling. Did you PS tighten your muscles (plication)?  Speak to your physician and get their feedback since they manage your care. A revision can be done if you're still unhappy but I wouldn't recommend that for at least you're six months out from surgery. 

Plastic surgery is not a treatment that shows results immediately, and sometimes you have to wait months. Obviously a breast augmentation you can see results right away. The same for a breast reduction or a breast lift. In contrast, results from liposuction and tummy tuck are not appreciated until 4 to 6 month post-surgery. Best wishes